Most of what ucbalumnus posted is completely irrelevant. But the Maryland policy (bizarrely, in my experience) is especially harsh on its face for students whose parents move while the student is enrolled. There is no automatic grandfathering of such students, something that most states do.
As a practical matter, residency is determined when a student first enrolls, and there is no automatic redetermination of residency every semester. If the university never finds out the parents have moved, it is unlikely that residency will be redetermined. All of the redetermination petition procedures – unsurprisingly – contemplate a student classified as out-of-state petitioning for in-state status.
Unfortunately, the rules state that a student must inform the university within 15 days of any event that may alter in-state status. I bet that rule is honored more in the breach than in the observance when it comes to parents of enrolled students moving to another state. As a technical matter, once the parents are no longer Maryland residents, there will eventually be a presumption that a dependent child is also not a Maryland resident. That presumption can be rebutted, but as I said there is no automatic exception.
In any event, under the rules, even without the exercise of any discretion, residency status is good for any semester the last registration day of which is within one year of the date the parents abandoned their Maryland residency. Depending on the exact date of the move, that could mean that the OP’s daughter is OK automatically through her 7th semester, and certainly through her 6th. After that, and assuming she plays by the rules rather than not informing the university, the student would have to prove that she did not enter Maryland for educational purposes and intends permanent residency. I can’t imagine that university officials wouldn’t agree with her in the circumstances described, assuming she has done things like voted in Maryland, rented an apartment there year-round, filed tax returns and paid taxes on employment income, gotten a Maryland driver’s license, etc.
If she is worried about this, it would be a very good idea to stay in Maryland and work there this coming summer, and not to spend it with her parents elsewhere. If she is still living in university housing, she should think about moving off-campus as soon as possible.