The Sage understands that this Sunday is the day that all the sons and daughters who have ignored their mothers for no particular reason feel obliged to e-mail them or perhaps send them a mass-produced card. People who have had good reasons to ignore their mothers will feel compelled to contact them, in spite of the damage it might do to their own psyches. And people who have tried to maintain good relations with their mothers will continue to do teh same this Sunday, regardless of the date of the calendar.
Some of these various people are this week's Seekers, who may be found here. http://www.slate.com/id/2252949/
1. The Sage certainly supports your feelings. How dare your mother have a failing prior to your birth! She should have been aware that you'd eventually been born and eventually find out. What did it matter whether her options might have been posing for these, selling drugs, or starving? She should at least have posted these pictures around your nursery, so it wouldn't have been such as shock now that you are older. However, the Sage suggests that you gently tell your mother how conflicted you are feeling about this. Together, you can work through those negative feelings. Holding this in will only harm you.
2. The Sage can't understand why anyone could possibly have been born to do anything more than remain tied to their mothers' apron strings their whole life, and to live as a serf under their patronage until inheriting whatever pittance they have saved for you. Unbelievably, your mother seems to be some sort of rare aberration who feels that her child(ren) should be independent adults. She actually expects you to put your own needs first, while somehow still caring for her and helping where you can. The Sage is at a loss as to handle such deviants, other than to honor their true wishes for building your best possible future.
3. The Sage finds your mother to be more the sort expected of most Seekers, rather than the loving, caring parents demonstrated above. This is an unreasonable demand being placed upon you, your sister, and the friend's daughter. Look into helping her apply for SSI or whatever welfare is available in your mother's state, such as foodstamps. The Sage accepts that your mother should not be the burden of the state, but if your permit her to drain you financially, you may be in need of such assistance yourself soon. If your mother was married to your father at his death, or for at least 10 years before the marriage ended, she may be entitled to some Social Security Survivors Benefits, which you father did earn.
4. The Sage agrees that people should be kind to others (despite the Sage's typical advice), but strongly disagrees that there is something inherently wrong with being popular. The Sage envisions that you were one of the "dorky girls" as a youth. Explain to the girls that even if the girls did not want to be their friend for some reason, she is still deserving of respect as a human being, and that you cannot accept their taunting behavior, even if it is not directly in front of this girl. Such things have a way of getting around until they get back to the target of such derision.