This is a hard one because she is a family member and you made the quilt without the intention of getting paid for it.
If it was someone you don't know asking for a quilt, it is easy. It depends if you want to make the quilt for sale or not. Many people enjoy just making them to give away. Once you start taking orders it can become a chore. This is under your control. If I don't want to make the quilt I ask for a lot of money. Usually I don't hear from them again.
I prefer to make a quilt I like and then sell it. When they start asking for particular colors the headache begins. If I decide to make the quilt I make them buy the fabric and the pattern (or at least select the pattern) so there is no possibility of confusion or the colors not being the right shade, tone or value. I am also very clear about the size. I explain that I then have to charge for hours of work, and I don't sell myself short.