I had a classmate of mine ask me to make her a quilt two years ago. She wanted me to design it, was very specific about the center block she wanted and some of the fabric she wanted included in it.
I did all the design work (gave her two to choose from) found the fabric she wanted, priced it all out including to have it longarmed by someone else (this was before I started my longarm business) and when I gave her the price....................... she hasn't really talked to me since! She didn't understand the cost of make a quilt that size - large king, and all the work. (She had also burned me with not paying for another craft I had made her years before so I had asked for 1/2 the money up front. So no big loss but my design time, in doing it.)
Make sure you get it all written out for your work and what she will be paying for. Friends are sometimes the hardest to make things for for pay.
Good luck.