I've worked with a food bank for years.
One thing I've learned, you really don't know all that well who has plenty of money. Sometimes people seem like they do, and then you find out the truth.
sometimes it seems like they don't, and then you find out they are millionaires.
I brought a bag into Church onetime with my donations and I saw a guy pick it up and walk out with it. It disturbed me. I found out a couple months later who he was and that he was under severe financial pressure. I think he was just too embarrassed to actually go into the food bank and ask, so he stole.
I guess that since you "know" this, don't let her take your donations in anymore.