My mother was very ill in a nursing home 2 and a half years ago Richard. I got a solicitor to the home and she spoke to my mother to determine if she was able to hand power of attorney over. She could not give a signature well, but was able to nod her head as a yes, and the solicitor from there drew up the Enduring power of attorney.
I think it is well worth getting a solicitor to go to the home and determine if she is capable.
I would not have been able to take my mother to the solicitors.
Its not very expensive, but may prove to be the best thing to do in the first instance