[Off the actual topic but, this is the bit I don't understand: Why would they give cash to your mother as a Christmas present? And then why would she want to buy them something with it? It would make more sense for them to just keep the money and buy what they want.
I guess the easiest way to answer that question is, that's just the way my mother is.
As for why they gave her cash, Mother is on a fixed income. She won't accept cash from Sissie and me, so we have to get her gift cards from the grocery store or else just pay for someone to come do her home repairs or whatever. Mother is notorious for trying to find ways to give back the gifts she's received. I gave her a gift to a clothing store for Christmas, and I bet you money when I take her there, she will try to use that gift card to buy something for me — which she is not going to do. Unlike Mae, I don't mind making a scene.