That was a generous offer from her, but I'm not sure I would want her to redo it. I would redo it myself and move on down the road. It's possible that this is the first time for this outcome and everyone else is satisfied with her work. I think your note to her was nice and got the point across without any accusations. You handled a sticky situation very well IMHO. Hope you can get it fixed without too much trouble and work.
Sue