Someone above suggested that PofA not needed between married partners, but I think the need for this has been amply demonstrated by Saxifrage.
We did ours years ago - we are the first named on each others', and the children are also named.
I have had a problem when discussing financial things as the credit card company, for instance, needs to speak to my OH and have him OK them discussing things with me, as he is the first named on the account. My OH has no clue at all about our finances and cannot use the phone very well, but so far, when needed, he has come to the phone to confirm that they can deal with me. It is only a matter of time before I will need to invoke the PofA in such circumstances.
Please get them done asap - and certainly before any diagnosis is reached. I did ours myself without a solicitor and had no problem doing it.
Preston Davey, another baby P.
Adult kids staying and not contributing.
Bereavement wipes out everything

