Don't use your own fabrics...make a list of ALL the necessary supplies you will need, backing fabric, setting fabric for the blocks, borders, thread, batting, etc. and don't skimp. Then estimate how many hours it will take to piece the quilt and add that figure. Then add the time it will take to quilt it and add that figure. Add a reasonable figure for "incidentals" such as a new blade for your cutter, new needle for your sewing machine, special thread for the quilting, etc. PUT IT IN WRITING. If she wants you to continue with the project, ask her to sign it. Then it's a contract.
I'm going to be surprised if you hear from her again. These are not cheap projects.