Ask to see samples of their work. I don't quilt a lot for other people, but I take pictures of my quilts and have several of my own that I can show them. Talk to friends that use a LA quilter and get them to recommend someone and look at your friend's quilt. Even if the quilter quilted from the back of the machine, she should have been checking the quilt for any problems. If you talk to her and she acts like she doesn't want to fix it or doesn't know how, take the quilt to another LAQ. It probably can be fixed and the needle holes won't show after spritzing with a little water.