If grandma is giving away all of her money, who is responsible for paying for her care once her funds are depleted?

Please don't take this as me being cold and unfeeling, but I believe that our family is at the point where we need to make sure our futures are safe and secure. Grandma is currently in a NH with the possibility of being sent home if she continues to progress in her physical therapy. There are suspicions of A/D, but no diagnosis. Since she has been in the nursing home, we have discovered that a particular family member has been receiving lots and lots of money (20 years and no contact but all of the sudden they are best friends....). Her POA has taken control of her checkbooks and credit cards to prevent this from happening for now. She only has enough money saved to pay for about 6 months of NH after Medicare runs out. We are concerned that if they send her back home, the leechers will be back and will drain her accounts very quickly. She is aware that we are concerned about her financial situation, but she does not care and still thinks she needs to "pay people who visit her." None of this money is coming to our family, but yet we are expected to take care of her. We cannot financially or physically take care of her if she requires NH care. So my question is this - who is responsible to pay for her care once her money runs out? The NH made the POA sign a form saying he is responsible for her, but he does not want to be responsible for her, especially when she is blatantly giving her money away to everyone but the POA. Not getting money from her is not really the issue. It is more that she is giving her money away to people who are basically stealing from her and all the while she is treating her POA like crap and then expecting him to financially support her when her money runs out. What legal obligations does her POA (or her immediate family) have when her money runs out? How do we protect ourselves from whatever happens as a result of her selfish behavior (please note, the selfish behavior is not new, we just added the A/D symptoms to it!)?