This morning when I went outside I couldn't hear her so went to investigate. She wasn't there. She was in a fairly substantial pen with a six foot high fence and the gate was still closed. For a moment I feared that she run away and then thought well of course she would head straight back to the others and there she was.
When I looked at the pen again I can see a few spots where she may have got out. Mind you, I think that she created the holes herself. Still they are pretty high up.