Safety in numbers. There was also the fact that regular cops wouldn’t bat an eye at some parents being witness to a few questions.
Once her mother is gone, she regrettable pulls Wendy out from under the covers, and her mind wonders if she could just barricade the door for a while more. That wouldn’t be received well, and it would give the game away.
She pulls out her phone, writes a message and speaks to Wendy at the same time.
"I think you’d better sneak out the back while I talk to the cops. My parents won’t see you. Don’t worry. I think… I think you’ve been in enough danger for one night." she says; rubbing the girls arm tenderly.
To the others, she writes a message:
Lily: Cops at my place. They say something happened to one of you! Bullshit?