Not only is it custom quilting, but you have to quilt on her lines and there are lots of starts and stops. If the design is not very intricate, I would think at least 3 cents per square inch, plus an hourly charge if you have to layer and baste the quilt. If you don't want to deal with burying the thread for all the starts and stops, you might tell her that you will leave the thread ends long enough for her to bury.