Is there any way to get Power of Attorney if my mother goes in and out of her dementia?

Is she rational for fairly long periods of time, I mean acouple of days at a time? The reason I ask is that my mom would have good days and not so good days where there would mild to moderate dementia, I knew she was declining but it seemed that no one else was acknowledging it including our family attorney. It might be possible to speak with an attorney that knows you and/or your mother and understands the situtation, let them deciede if mother is still cabple of understanding what she is signing and willing to sign. Attorneys are not qualified medically to make a diagonisis, however they are capable of working with you in determining if mom can still express her desires. By no means go this route if moms ability to make decisions is be on reasonable. My mother was definitly having problems in some areas but still able to clarify her wishes in others. It's worth a try, if she has been medically declared as having dementia it would not be ethical or legal to have her sign anything. Having said that then you would have at aleast the beginnings of the medical proof (expert evaluation) needed to look into guardianship procceeding. By the way Lilliput is a smart gal and gives us all good insight. Hope this helps, I am just starting to work on guardianship for mom, let you know what I learn.

If she has been professionally assessed with dementia or "diminished capacity," then, no, I do not think that she can sign legal documents.
There are other avenues if you need to provide protection such as guardianship. This is a much more involved process but is more comprehensive than a POA.
I would highly recommend consulting an elder attorney.
good luck