As was mentioned below, the new property has to be inspected and not all renters accept vouchers. So if your friend's moving is a need and not a want, she should be prepared for a potentially extended process before she is in a new place.
I would like to say though, Charles County have very few rental homes accepting vouchers. When searching for a property for clients I tell them they can not be picky because my search usually finds 2 maybe 3 homes that will work. It might be best if she can stay in the home she already has.