@Findmoreinfo - you have already received great replies regarding taking the ACT again. I am just tossing out one other thought since you are asking about standardized tests: has she taken any SAT Subject Tests yet? Although they are recommended and not required by Stanford, you might want her to look into those for this spring, particularly if she is taking some courses (such as AP Chem or AP Lit) that might correspond well to some of the Subject Tests.