I agree with Charismah and others who advised you to talk to her. As a Newb myself I would want any feedback on quilting I do for others, good and bad. However, there is a distinct difference between feedback and nit-picking because you don't like the quilting design. While I agree the star quilted in the big white center is sparse, it is not bad quilting, the tension looks good and the lines for the most part are straight. She looks like she was trying to do ruler work which isn't as easy as you may think. If you had absolutely no input or suggestions in how you wanted the quilt quilted the responsibility does not lie 100% with your LAer. If you were not specific in how much quilting you wanted those white squares quilted or if you envisioned a feather wreath in the white squares but did not say so that is not the fault of the LAer. It is a learning experience for all of us. Some beginning LAers just don't realize the balance needed in quilting. While some quilts will look great with densely and sparsely quilted areas combined, there still needs to be some balance. You said you were happy with the other two quilts and you need to let her know that as well and why you are happy. You need to be very specific about the areas you are not happy with on the 3rd quilt. "I just don't like it" won't cut it. Do you like the star but just feel there should be more background fill? Say so. Do you not like the star and want a feather wreath or feather heart in the area or a stencil motif? Say that too. Perhaps the agreed upon price did not include something as elaborate as you envisioned. If that is the case you and the LA also need to discuss it. In my mind the biggest problem right now is lack of communication between you and your LAer. Your quilt is completely fixable and not ruined and I am sure she will appreciate the opportunity to make it right for you. I would be mortified if I quilted for someone and they were unhappy with what I did and never told me.