Tell her to talk to someone more knowledgeable, like a teacher or careers adviser or something at your school/college. She should have spoken to them already really, because if she was aiming that high she should have been considering getting things remarked.
She can still apply to RGs and have a really good statement and put in for a bunch of retakes and still have a shot at getting an offer at one, but it'll be a stretch and be highly dependent on her GCSE grades and her predicted grades.