You created the mother's character with strong presence, in just a few words. I think the fact that she is the only one with a physical description is a part of that, but the details of her actions helped, tapping her foot, for example, and the way she goes back for the rest of the cash. This is a flash fiction, but you elicit an entire world and mother-daughter dynamic (by choosing the exact, tip-of-the-iceberg details and information we need to see that world) so that it feels like a much longer story. Nicely done.