Pharmacy Questions? Ask a Pharmacist Online.
How old is your sister? and what dose of Adderall did she take?
In the long term it can be dangerous. In the short term, there is likely no need to worry. It can lead to heart tremors and can affect the way the heart beats. Assuming she has no cardiac conditions and that she does not take both regularly, she will just lose her appetite, get sweaty palms, and won't sleep very well.
Is there anything else you were concerned about?
Please remember to leave a good rating. I am happy to follow up with any additional questions.