The 3 million dollars is your mother’s to spend as she sees fit. While your father worked hard, I am sure that she did as well with 5 children to raise. She is fortunate that at 89 she is competent and can still enjoy herself.  She may choose to leave more money to one child than another.  She absolutely does not have to save money in order to leave an inheritance to her children.  I am reading the post as your mother goes on the trips and dinners with your sister, not without. If she is accompanying your sister, this is not likely elder abuse. If she is making gifts to your sister, then it still may not rise to elder abuse.  Your mother would need to be incompetent. However, if at some point in the future your mother needs nursing home care she may need to apply for Medicaid. With the five year look back, those gifts will disqualify her from receiving benefits unless your sister can refund the money. You should have your mother consult with an elder law attorney.