As a longarm quilter, I want my customers to be pleased with what I do for them. Did you talk to her about the quilting you wanted when you took it to her? I would suggest taking it back to her, telling her you are disappointed with the amount of quilting on this quilt and ask her to add more quilting to the quilt so it will hold together with the use it will get. She could do the same squiggly lines going in the opposite direction to make a grid which would help hold everything together. It is easy to put a quilt like this back on the frame and fix it.
Most of a quilter's advertising is word of mouth and if a quilter wants to stay in business, they need to listen to their customers and give them what they want. Personally, I would rather over-quilt a bit then to under-quilt a quilt. Please give your quilter a chance to rectify this situation. I've had a customer return a quilt that I just flat missed a corner of echo quilting on...I felt stupid, but immediately fixed it and now she brings all of her quilts to me to quilt. We want you to be happy with our work and your quilt, and if this was me, I would feel awful that you weren't happy and would want you to make me aware of your displeasure so I could make it better.