From my perspective this all seems to be caused by the lifestyle she lives and her immediate surroundings - she's like under constant pressure to behave the way the rest of the ppl expect from her and she cares too much about what other ppl think about her. Another cause which I think is quite relevant is that she doesn't have much friends or hobbies of her on own so she's too dependent on my father who mostly cares for himself.
I'm trying to talk to my larger family about this problem but most of the time they just dismiss my claims about her not having a good life, cause they don't want to make more of a drama by talking to my father to change his habits - they see it like everything is ok and the problem is with my mother who is just mentally ill. This is escalating as I'm slowly getting more and more reluctant to even talk to my farther, sister and the rest of the people who don't see this as a problem. I'm even thinking of translating articles like this so they can read this and possibly understand that's not everything is about drugs. Any ideas of what can I do are welcome as this is the source of my depression and anxiety for quite some time.