What do I do if my MacBook gets wet

FWIW. I had an accidental water spill on my 2020 MacBook Pro. It was only a small amount of water, but I could see that it had affected the notebook's display. I did all the typical things to try to remove as much water as possible. I too waited a few days, but the issue still persisted when I powered it back up. The end result is that it required a new screen, logic board, & track pad. Fortunately, having AppleCare+, the repair costs were manageable.

I'm not saying that this will necessarily be the case for your daughter's notebook, just making you aware that simply leaving it to dry may not be enough. Once a liquid enters into the notebook, even if it evaporates, it could leave trace elements that could be conductive. Their presence will increase the likelihood that even more damage is still possible should she continue to use it. Although, inconvenient, having it looked at by the Genius Bar or an Apple Authorized Service Provider is the next best step ... unless, of course, you just want to purchase her a new notebook.

I would second ku4hx's comments. One thing in addition, I would strongly recommend is to stop using it and be sure it is powered-off before you pay your local Apple Store a visit. Any further use could cause additional damage.

Depends on the severity of the event. Having given no details, take it to Apple for evaluation.