My parents are crazy.?

If shes in her late forites or fifties she might be going through menopause. Menopause makes you go through changes, sometimes happy, sad, angry, really angry, sweating, not sleeping etc...Or it could be that she just has other issues and needs some vitamins and to work out. Continue to let her stay with you and watch her because she may be going through a depression especially when they start secluding themselves. Tell your sister to stay strong and get good grades. Her grades are her ticket to college and away in the dorm life. Just keep wathc over her.