John Doe, you're so right, but I should add that half the reason she wanted to hear a "thank you" was so that she knew they had gotten the gift. Last Xmas I got a gift from someone who sent me some filets from a steakhouse and inside the box there was a card suggesting that I call the sender to let them know I had gotten their gift.

Incidentally, these people that she's done business with aren't people who gave her business, but people to whom she's given business. These are people she has paid for a service and not people who have paid her, but I guess it works both ways