Bonnie,
Did this take place in New York? I am suprised.
There are some great attorneys in New York that may be able to help you.Have you spoken with your friend and asked her what she wants to do?
Because all in all she still has the right to make those decisions. If she wants the step daughter to have POA there is nothing anyone can do about her choice.Unfortunately that is still one of her rights. Is she still on the psycho tropic drugs you named or was that a breif duration, because if she is not on these drugs now, you should speak with her and see if she in fact wants any help. If she does you can contact an Elder abuse attorney or in New York a Geriatric specialist could also help. If she does not want the help then sadly your hands are tied.