Writing a character out is always easy… question is, is it a good idea to have this girl in the show in the first place, considering?
How old is she? If she is worried her parents will pull her than it’s logical to conclude she’s young enough that her parents still have control over such things. If that’s the case, and you use her anyway, it may be possible you could face legal repercussions for using a minor with out parental consent.
It depends on how far the parents want to push, but if they do push, the law will be on their side. Child labor laws are pretty strict.