I agree with everyone. Rip it out. I had the same thing happen to me, my quilt looked like a 3 year old was playing with momma's machine! When I brought it home to show my husband, his first words were "Was she drunk?" his second words were "You are going to rip that out, aren't you?" this from a man who doesn't even know what I do in my sewing room.
Don't worry about saving her feelings, save the quilt. Don't mention it to her. If she ever visits and sees it she will think she did an amazing job quilting it.