Oh yeah, I was that daughter. Ran away at 13, was gone for 5 months, lived with a motorcycle gang, in a drug house, lived in parks.
But my home was less safe, trust me. It was an abusive sick place. I was only glad to be out of there.
This is why i say to trust that she's ok. Firstly, what else can you do? Drive yourself crazy? And secondly, I made it through some very intense situations.
This may be a good thing, if you think about it. If you handle it well.
good luck. And dont' kill the boyfriend!