I would give her the pattern requirements and have her buy the fabric, batting and backing with a little extra of each fabric. She can buy it over time if she wants to use coupons. Once she has all the materials you will make the quilt. $15 an hour sounds fair. I have had a couple of people ask me to make a quilt for them, when they find out how much fabric is, even with coupons, they change their mind. She probably has no idea how long it takes to make a quilt. I would give her an estimate of the number of hours it takes to make a quilt that size, telling her it may take longer than the estimate.