potty in bed

So woke up last night to Amy crying. Ran into her room and found her squatting on her little bed, and her pull-up pants pulled down. She apparently thought she was on the potty, because she was mumbling "potty, potty." She managed to soak everything (blankets, sheets, floor, mattress, mattress pad) except her pull-ups. They were still nice and dry and I was able to reuse them...