Power Of Attorney Question

Location: Virginia, USA

I have power of attorney for my elderly mother who is suffering from vascular dementia. She still recognizes me and can talk to me, but she doesn't understand where she is or when it is. She talks about the memory care center where she lives like it's her workplace, thinks one of the nurses is her old boss, etc. Conversations wander all over the place and only touch briefly on the present reality. She still enjoys our visits though.

I have power of attorney and have been managing her finances for the last couple years. I manage the monthly payments to the memory care and pay the pharmacy bills. Occasionally I make purchases like clothes or toothpaste when she needs something.

I am one of 4 kids who all love her very much and want her to be as comfortable and happy as she can be. (I only have the POA because I'm geographically closest.) In past years, as her mental faculties declined, I helped her and my Dad buy Christmas presents for all the kids and grandkids. This year, because she's declined so much, I was not planning on doing anything - certainly no one is expecting it. And Mom doesn't really understand that it's even Christmas time. But my older sister "Natalie" is dealing with a lot of financial issues (she's married with kids and a mortgage, but her husband has decided not to work). If Mom was herself, I know she'd want to send Natalie a nice Christmas gift - a check or a gift card. She's done this in the past when Natalie's family has struggled.

So that's my question. Can I do something like that on my Mom's behalf? I could definitely talk to my Mom about it and get her consent, but I'm not sure what that would be worth in a court of law. Is there a dollar amount I should stay under? I'm sure even something like $100 would help.