Sleeping in the floor...

The other night we went to check on Lizzie before we went to bed and Russ almost hit her with the door. She was sound asleep with BaBa on her rug right by the door. How does this happen? Was she running full steam ahead and suddenly fell over in exhaustion? Was she laying on the floor contemplating the mysteries of life with BaBa and just fell asleep? Hard to know what goes on in her brain...