There is a lot of good advice on this thread.
But I think before you try any of it ask her in a casual way why she does not come in when DBF is there. If she just shrugs tell her it is ok to tell you why. If it is because she just does not like him tell her you will never tell him.
If she is fine with DBF ask if everything is ok at school. Tell her you really need to know what is wrong.
But I think before you try any of it ask her in a casual way why she does not come in when DBF is there. If she just shrugs tell her it is ok to tell you why. If it is because she just does not like him tell her you will never tell him.
If she is fine with DBF ask if everything is ok at school. Tell her you really need to know what is wrong.

My DD sleepwalks. She will carry on full conversations and travel all over the house. We have even taken to deadbolting the door and putting the key out of her reach when she tried to leave the house one night. She appears to be fully awake, eyes wide open and chatting. She has absolutely no memory in the morning. We know she's asleep because sometimes her conversations make no sense or she's addressing us as if we were her buddies. We have also found her watching TV in the middle of the night but she never changes the channel from the last one that was on. 


Don't let it stress you!