Can Dependent leave for studies while AOS pending?

[sassydoc]

My application for Adjustment of status is pending. In the meanwhile, my daughter has to go back to her home country to study medicine. Can she leave USA before she is able to adjust her status for the purpose of studying and yet be eligible for adjustment of status?

She is 19 years old and i am afraid that if she is not able to get AOS, then she would not be able to get her immigration since the consular processing may take a while.
Would appreciate your comments and thoughts,
thanks in advance.