My 82 year old mother was convinced to give my sister POA last year expecting she would do the right thing and take care paying her bills. However, upon my mother going to her own bank and being denied her own money unless approved by the POA, she decided this wasn't in her best interest & proceeded with the revocation process. After giving her bank a copy of the revocation she is still being denied her funds & my sister seems to come up with every excuse not to be able to take my mother to the bank to withdraw all funds. Much to our surprise the same sister has convinced the Social Security Administration that my mother has dementia and is unable to handle her finances which in turn made her the Representative Payee. After seeing a true dementia patient I am convinced of quite the opposite. The disturbing issue is that my mother is well aware of more than I seem to be sometimes and if she was incapable then how would she know to question my sister's intentions? The bank seems to have ignored the revocation & now we need a second opinion on the dementia due to the same sister convincing the doctors of my mothers so-called "incompetence".
I also wasn't aware that having financial POA means a person can be denied access to their own money. I suppose this may be true if indeed they are declared incompetent, but I also assume that your mother has told you what she wants to spend the money on and you agree it's something prudent and your sister isn't disagreeing on those grounds.
As others have said, she can be held accountable for what she spends money on... or, according to my understanding, what she doesn't. From my limited reading, it seems she's not only responsible for not spending the money in frivolous manners, but also in making sure the money is used to get your mom things that she needs. IOW, saving money, yes, but not saving it to the exclusion of not meeting your mom's needs. I don't know how the law views it, but ethically I would think that would include specific requests your mom has, assuming the money is there for them and they are reasonable (no fur coats if there isn't much money, but if she asks for a more comfortable pillow to replace an old one or suitable dressy clothes to wear to nice occasions or something and the money exists, why not?).
Mom must be with you and I would recommend getting a letter from her doctor that states she is not incompetent. If the doctor is taking your sisters word over the reality of moms situation, turn the doctor into the board of health and get a new doctor asap, be very sure that it is a scam though, ask to see test results that led to the diagnosis. If mom is with you she can sign a HIPPA release so the dr can discuss this with you. Dementia does not equate to incompetence. Anymore than POA equates to entitlement. I would like to add that someone can seem perfectly capable and question someone's motives and not be able to handle day to day life, including money.
Good luck getting this straightened out for mom, has to hurt her heart that a daughter would hijack her money and declare her incompetent when she is not. I guess I would want to know exactly what is moms diagnoses and get myself educated on that before I created WW3.
Take the revocation papers and anything else you have pertaining to the POA to the attorney. Make sure Mom is present at the meeting. Sister probably should be as well to state her own case. POAs MUST divulge what they’ve done with the person’s finances including and especially showing receipts and the expenses had better all be for the person they have POA for. Sounds like sister is hoarding money.