I called her into the room but was still very groggy. She got in bed with me for a minute and then went back out in the kitchen. "Weeeeeek!"
When I attained a more complete state of consciousness I went to check on her. She normally doesn't make that kind of noise and she seemed distressed. She came over to me, let me pet her, rubbed on my shins. She seemed okay, so I went back to bed. The noise continued.
Finally, I had the Eureka moment. Pretzel had snuck into the basement and been locked down there. She was crying because he was stuck on the other side of the kitchen door. She's such a good sister.