What rights do I have and/or can/should obtain regarding my mothers health care and finances towards such.

My monther, suffering from Stomach Cancer, is mostly bed ridden at home. She is under the care of home care agency and has around the clock care. They contacted me on Monday to inform me that she had not eaten in three days, had not had a shower in two weeks and would not always let them change her diaper. In additiion to not eating she had not been taking in water and only drinking alcohol and spent most of her time intoxicated. She is too weak to go through detox and we want her to live out her remaing life in the comfort of her own home. She fights us on every change. What can I do to make sure that I can make the decisions to insure that she has the care she needs and that ehr funds go towards this?