Since dad passed my sister's been acting as POA. Isn't moms safety with regards to handicapped surroundings as important as financial?

Yes, your mother's safety is paramount, and her money should be spent for her care. As mentioned, greed can make some adult children "protect assets" when the assets belong to a parent who needs the money.

I'd talk with your mother right away about having both the financial and health POA legally assigned. She needs to give this power to someone she trusts. If a family member can't be appointed, an attorney or even a bank officer can take charge of the financial end.

Do talk honestly with her now. If she is confused, see if a trusted friend can help her understand this need.
Good luck. You sound like a caring person,
Carol

Yes your mom's safety is what is important. Unfortunately some siblings rear their ugly heads when it comes to taking care of their parents - such as my brother-in-laws did. All they cared about was how much of the money is spent - not whether she needed it or not. So we had to get Financial and Medical POA to ensure she was taken care of appropriately and so they wouldn't rob her blind too. You may want to talk to your mother about changing the POA to you or someone else your mom trusts if your sister is lacking in taking care of her. A POA can be withdrawn or changed at any time as long as the person is of sound mind. And you say she's "acting" as POA. If it isn't documented, she shouldn't be doing it at all. Good luck!!