Things That Go Bump In The Night

We moved Sophie out of her toddler bed and into a twin bed.  We knew she was really too big for the toddler bed but she wasn't complaining and we weren't quite ready for the shift to a bunk bed.  We found a nice girly ping bunk bed with hearts that was perfect.  Genevieve has been very excited to have the top bunk.  Sophie has been excited to be in a big bed and to not have rails on the side either.  All was going well until last week.  Carrie was cleaning up from dinner when she heard a loud thump.  She ran upstairs to see what was going on.  She found Sophie on the floor, wrapped in her blankets, fast a asleep.  Carrie picked her up, put her back into bed and tucked her back in.  Sophie didn't even notice.  We asked her about it in the morning; she had no recollection of the event.