Age 81No kids of her own. We’ve never had a closer relationship but since dad died, I call several times a week to check on her. She is lonely, depressed, threatens suicide. Her short term memory is gone. Sometimes hallucinates. Lives on her own and does not want to move anywhere. Lives out of state from me. I worry about her ability to take care of herself. Does not accept help from others.
I, personally, would not call this woman my stepmother since she had nothing to do with raising me. I would call her my father's wife when talking to APS or 911. IMO, stepmother gives the impression of closeness and you say there is none between you. Make sure if you do talk to anyone, that you are clear you will not take on her care, you are just concerned.
Ideally, if you are interested in being her PoA and she's willing to assign you, this should happen before this medical appointment.
In the end, if she is uncooperative on all fronts you will really have no choice but to report her to APS and allow them to maneuver her into appropriate care. You can technically have all sorts of legal authority to act on her behalf but if she physically will not cooperate, then things get exponentially more difficult in getting her care. Then you'd also have to figure out if she has enough money to pay for that care. If she gets assigned a court-appointed guardian, then you don't have to worry about it going forward.