Kids do nothing financially to help mother

What will happen when she dies and has no will. Her deceased husband wanted the home to go to her daughters son, because he was abandoned by both parents. The son is very well off and does not give her a penny for help. She has a home equity loan $50,000 and has applied for V.A. benefits. After she pays me she has maybe $200 left. She has given her son $15,000 after her husband passed. The daughter has helped a little. I am afraid that the son will throw all of us out and I will be homeless and without a job. She wants to let grandson and my daughter rent the finished basement for $500 a month. This could go toward paying back the loan, so it would be like rent to own. She has no will, minimal life insurance,i have saved her hundreds of thousand of dollars, by getting her real estate tax reduced, hardship case and medical bills removed. The son hates all of us and I know he will through us out and take everything, giving his sister nothing also. She said I do more for her than her own kids. I do not want to pressure her with legal issues but things do need to be addressed. HELP She is mentally sound and sharp as a tack.