Found this post in the search and I can feel for you and your mother,
There are something you have to know.
My aunt has had a major despressive disorder since her early 30s after being fired in her company. All those medicine did not work on her and quite oppositely, she ended up in a hospital for a few years (can't remember as I was little) and that hospital was horrified where she was isolated from all the healthy people. And now she can only stay in a house and cannot go back to the society anymore. Her parents regret all the time that she did not receive help in time or she might be a normal healthy person today.
I remember when I was a kid, she seemed to be so amiable and I counld not see anything wrong with her. But now I have moderate depression, which is a irony as my parents sometimes blame me just like my aunt, and I am an insider who knows better than anyone that depression is a disease you can hardly tell from one's appearance.
So please understand that even if a patient who has depression smiles to you or appears to be calmed, he or she may have dramatic pain and struggling inside combining with shame for the disease. I can constantly feel the pain in my chest, throat and head. I burst out tears when I go back to my room alone and yes crying out makes me feel relieved a bit. In the everning, sometimes I feel I really cannot breathe and my whole body is incredibly uncomfortable and itchy. When the symptoms reflect in a physical way, it is no longer a mild depression.
And I was living in a student flat last year and was bullied by a flatmate who often got so dramatic. I understand how awful that situation could be.
What I could suggest is first, she needs someone to make her feel less helpless and support her unconditionally, idealy a professional counsellor and second she has to rest and not take pressure for a period of time. A lot of people's depression get worse because they can't take a break to receive a decent treatment year have concerns about their achievement in work or study.