I'd say give the quilt as a gift. If she insists on charging, or if you need the money, then charge her the amount for just the supplies. If she's like my grandma, she'll pay you that price, plus whatever extra she wants to throw in.
I feel uncomfortable charging money to family for most things. In our family, we are constantly helping out one another. I could charge my brother for the baptism dress I just made his daughter, but then how much would he charge me for a day of labor moving all my boxes when we came from CA? What price can you put on the time, energy, and love that family puts into each of our lives?