For that amount of money and time I would choose a real simple block like a nine patch, shoo-fly. yellow brick road or something easy.
And I would look for some real bargain prices too. I once made a generous queen/king log cabin quilt for a perfect stranger and charged way too little for all my time & effort. I learned a lot from that mistake. On the other hand I have given a lot of quilts away as gifts. You're a good-hearted person to consider her situation. Good luck with this project.