My fees for handquilting start at $.10 a square inch and go up depending on how heavily they want it quilted. I would also charge them for the materials, batting, backing, binding etc. I have a friend who has gotten as much as $1000 for handquilting a large quilt. I am close enough to the Lancaster PA area to have seen how much their quilts go for. $1000 is not an unusual price for a large quilt.
I suggest she take her friend to a quilt store and let her get an idea how much the materials etc. would cost. Perhpas they could work out some kind of barter situation.
I had to laugh a woman who sings with me in the church choir mentioned that a mutual friend had taken her to a quilt shop and talked her into purchasing the materials for her first quilt. Of course the friend is going to help her with the project. She was horrified that she had spent $80 dollars. I admit I rolled my eyes and laughed. If she get the quilting bug that will seem like her cheapest project.