At work, my mother experiences that she is being ignored by most of her co-workers. She feels isolated and sad. What can she do?
In Buddhism, the heart is judged by its own virtues (goodness) rather than by what others think.
Therefore, your mother should develop faith & trust in the virtues of the Buddha (rather than be concerned about what others may think or not think about her). If your mother has the virtues of Dhamma (such as non-killing, non-stealing, non-sexual-abuse, non-lying, non-greed, non-hatred & gratitude) then her heart will have well-being & inner-respect.
shunning someone at work is a form of office bullying.
complex issue. How about bringing donuts or something a little exotic to work for everyonce in the morning everyone in awhile? worked for me. one of results of karma of giving that can be seen on the here and now is generally loved by others. And interestingly, in one of the responsibilities employer should do to treat employees is offering exotic tasting food (special food on occasion). This part makes me smile when i read it because it is so true. One of many ways to captivate others.
It is important to understand that life of a Monk will never be subjected to such a situation, and he will not have to worry about them. Being isolated and thinking deeply about existential questions and understanding how things work is the way of a Buddha. Therefore, one who is pure at heart and one whose mind is as calm as still water will never let the toxic negativity around him/her affect their composure. Given that you and your mother live in an ordinary human society built by these modern ideologies, it is impossible to live the life of a Monk and it is quite likely to meet hardships.
In a society filled with people who have feeble control over their thoughts and mind in general, it is not uncommon to find people who do not treat others well. Therefore expecting perfection in people around us, in this modern society is futile, and the only way to remain happy will be to focus on ourselves and more specifically our mind.
So what must be done:
Accept the reality and understand that associating a negative emotion with something is the real problem here. Please tell your mother that I requested her to sit silently for a minute, close her eyes and be gently aware of her breath. This will help clear her mind. Now once she had done that, please ask her to forgive her colleagues by saying the following to herself: "I forgive my dear colleagues for ignoring me. I do understand that my colleague's lives are filled with worries like with everyone living in this modern society, and their negative emotions and ignorance of my presence are simply nothing but a reflection of their struggles and sufferings. Therefore, I consciously realize their suffering and feel sorry for them. And above all, I would help them if they need me. This cycle of suffering which spreads from one person to the other needs to stop. Let me help by playing a small role in doing so"
Doing this is most likely to relieve your mother of her sadness.
It is important to understand that the world we live in is filled with negativity. Emotions spread like a virus. So it is very important to end the negative cycle wherever and whenever possible. This can only be done if a negative reaction is forgiven wholeheartedly.
Sometimes, the thought that the world is negative, and the people around us are all negative and conspiring to hurt us, is a delusional thought caused by expecting something negative to happen to us all the time. This is another consequence of the world we live in. We are confronted with negativity more often than we are confronted with positivity. This forces us to keep doing the same.
Everything we observe will have both a negative side and a positive side to it. For example, you can either say that a cup is half full or half empty. Focusing on either of them while neglecting the other will be a big mistake. Understanding that every perspective has something important to tell us and looking at things in all the possible perspectives (including its negative side and the positive side) will help us understand the situation with a greater clarity.
When thinking goes wrong, one suffers. If one thinks about what he/she does not have, desires for it, developes ideas of "I would have a right", "I deserve that", then misery increases and often unskillful actions in words and deeds follow. Such is a poor person, no matter how much he/she possesses and destinated to poor realms.
If one on the other side thinks in terms of what he/she has, even in terms of what he/she can give and shares the wealth he/she has like one who can, then that person, however less he/she might own, is always a most rich Deva/Devata. No possession of wealth, regard, honor and wellubeing can excel his/her's.
Not knowing much of your particular case, but it's obvious that your mother owns or has got something better, which not many people gain from their child, namely, the care of her daughter.
So try to learn be generous and think in good ways:
There is the case where a certain person is not covetous. He does not covet the belongings of others, thinking, 'O, that what belongs to others would be mine!' He bears no ill will and is not corrupt in the resolves of his heart. [He thinks,] 'May these beings be free from animosity, free from oppression, free from trouble, and may they look after themselves with ease!' He has right view and is not warped in the way he sees things: 'There is what is given, what is offered, what is sacrificed. There are fruits & results of good & bad actions. There is this world & the next world. There is mother & father. There are spontaneously reborn beings; there are brahmans & contemplatives who, faring rightly & practicing rightly, proclaim this world & the next after having directly known & realized it for themselves.' This is how one is made pure in three ways by mental action."
and give your mother that what really repays what you owe her. And by explaining to her what is right thinking, she will be a wealthy well-regarded person for long long time.
"I tell you, monks, there are two people who are not easy to repay. Which two? Your mother & father. Even if you were to carry your mother on one shoulder & your father on the other shoulder for 100 years, and were to look after them by anointing, massaging, bathing, & rubbing their limbs, and they were to defecate & urinate right there [on your shoulders], you would not in that way pay or repay your parents. If you were to establish your mother & father in absolute sovereignty over this great earth, abounding in the seven treasures, you would not in that way pay or repay your parents. Why is that? Mother & father do much for their children. They care for them, they nourish them, they introduce them to this world. But anyone who rouses his unbelieving mother & father, settles & establishes them in conviction; rouses his unvirtuous mother & father, settles & establishes them in virtue; rouses his stingy mother & father, settles & establishes them in generosity; rouses his foolish mother & father, settles & establishes them in discernment: To this extent one pays & repays one's mother & father." (AN2.31)
That means if even you, as her daughter, got others not to ignore her & brought others to estimate your mother, you would not be able to pay back what you owe her. But if you are able to teach her right thinking, giving, letting go, not to demand: e.g. become a real person by her own, that you gave her what is really hard to gain and a auspicious future for long time.
Having gained the real treasures one becomes secure. Wealth, regard, praise, well-being... the eight wordily Dhammas, are not for sure.
By Attending to and serving just her good qualities and being careful and respectful to correct that of what is not right and possible seen as ugly on her behalf; you are not only a real good daughter, but a real admirable friend. A person who does her duties and gains release, step by step. One who serves the Buddha & the gods.
(A nice tiny story comes to mind, maybe able to translate when back from alms)
A son went with his old father to a restaurant for dinner.
His father was already old and weak, soiled his shirt and trousers while eating. Other guest looked annoyed at him while his son remained totally calm.
After he had finished his meal, his son - not having been embarrassed at all by that - brought him to the toilet, removed the garbage of food, cleaned the stains, comb his hair, and adjusted his glasses.
Als they returned the whole restaurant observed them while not saying anything loudly, not able to understand how someone is able to disgrace oneself like this in public.
The son payed the bill and went on torward the exit with his father.
At this moment an older man under the guests called after the son and asked: "You haven't had left something here, have you?"
The son answered: "No, I didn't."
The old man countered: "Of course you have! You leave a lessonfor every son and hope for every father behind."
The guest grow still.
My person thinks that one being a daughter, or any other person in a certain relation that deserves gratitude, will understand the lessons shared here as well, in each certain case.
Here are also the ten ways of subdoing ones anger, ones sadness, ones tears:
"There are these ten ways of subduing hatred. Which ten?
 "Thinking, 'He has done me harm. But what should I expect?' one subdues hatred.
 "Thinking, 'He is doing me harm. But what should I expect?' one subdues hatred.
 "Thinking, 'He is going to do me harm. But what should I expect?' one subdues hatred.
 "Thinking, 'He has done harm to people who are dear & pleasing to me. But what should I expect?' one subdues hatred.
 "Thinking, 'He is doing harm to people who are dear & pleasing to me. But what should I expect?' one subdues hatred.
 "Thinking, 'He is going to do harm to people who are dear & pleasing to me. But what should I expect?' one subdues hatred.
 "Thinking, 'He has aided people who are not dear or pleasing to me. But what should I expect?' one subdues hatred.
 "Thinking, 'He is aiding people who are not dear or pleasing to me. But what should I expect?' one subdues hatred.
 "Thinking, 'He is going to aid people who are not dear or pleasing to me. But what should I expect?' one subdues hatred.
 "One does not get worked up over impossibilities.
"These are ten ways of subduing hatred."
Now having cleaned your heart with the Juwels and the tools of the Noble ones, go on, and give a share of that brightness there where it might be dark at this time. For one having falled into darkness, how could he/she be a light. Having taken a real refuge one is no more able to fall into dark.
Mudita with you both rich people, and those having served that the lessons got possible good provided.
[Note: This is a gift of Dhamma and not meant for commercial purpose or other low wordily gains by means of trade and exchange.]
My heart goes out to your mother. I have meditated and studied Buddhism for 50 years and the deepest insights I have gained, even though I have had many, have to do with the nature of love itself. By far the deepest Buddhist teachings have to do with love. Your mother was born with love in her heart, as everyone is. She is ultimately sad because her love is being rejected. To want one’s love to be valued is not a form of “clinging” or “greed.” It has to do with our survival as a loving being. My suggestion is that she contemplate on the fact that she has at least one person (you) that loves her enough to post this question. But I can tell you about people in general (including beginners in the practice of compassion and love) simply have no idea of what love is really about. Your mother is being ignored by such people. One of the deepest meditations in Theravadin Buddhism consists in recalling the love that was born in your heart centre (chakra) by imagining an ember deep in the heart (which never forgets) and breathing life into that ember. Having contacted this innate love, I suggest you share it only with those who value your love.