Why on earth would she even rate it? I don't go around giving one star reviews to every high fantasy book for being about an ordinary kid that learns he has an extraordinary destiny. I could see if she gave it one star because she felt the writing was poor, or the story was boring. In that case I'd keep my mouth shut and just suck it up. But one star because she picked up the wrong book?
I'm going to go count backwards from 100 now.