There are also cheap alarms for just one door, in CA if you build a pool you must have one of these if you don't have a separate pool fence. I doubt they are very expensive. It will just buzz but it should be enough...unless she is smart enough to remove the batteries.

My daughter has lost some brain cells since turning into a teen...no offense to any teens on here but what the heck happens? Its like an alien comes to reside in their body. Of course not all teens go through this but quite a few seem to.