This is a hard one. The fine line between doing what you love to do, and charging for it always a hard line to cross, especially when they are close family and/or a friend. The best thing to do is to be honest and upfront before starting the project. This will alieviate any hard feelings down the road. Her giving you the cost of materials was very nice. The gift card was an added bonus for a great lesson. Enjoy your dinner and move on to your next project as a much wiser quilter.