I’d assume she would have submitted the strongest application possible to start with. So unles she wins some major award or she inadvertently missed putting something in, an appeal is unlikely to sucveed.
I don’t think parents do their kids any favors pushing for appeals 99% of the time. Your job is more to keep your kids on even keel, encourage them to have a backup plan they can be happy with, and help them move forward with a plan that might not be their heart’s desire. Those lessons will serve them a lot better in the long run.