Hey there I'm in the medical field. Don't let stop or alter her meds in any way. Especially during exams and in interviewing process. All she needs is documentation from the Dr./Drs. She won't have any problems. Just remember everyone has an issue.
Stim meds will show up in both urine and hair testing. Hair testing can go back 90 days. Urine tests will show use up to 5 days.
Having said that Title One of the American Disabilities Act should protect you. If you have a valid prescription and diagnosis and tell them before the test - I think you would be ok. But, it wouldn't hurt to check. I certainly would not want to work for any medical institution that did not recognize proper treatment for AD/HD.
By the way, Vyvannse has a longer time of duration then Adderall. Both work better with a high protein breakfast.
Hope this helps. Let me know if you have any other questions.