Mystery TV noises, or logic fails when my brain isn't firing on all pistons.
Laurel goes to bed easier when I tuck her in with a few stuffed toys. Normally I think about which ones I choose to avoid particularly noisy ones like Tickle Me Elmo, but I didn't think about it tonight. Thos came back to bite me about an hour later, when I heard a line from Dora the Explorer... then another. I tiptoed over to her door and opened it to find the TV and DVD player were off and Laurel was sound asleep.
A few minutes later, I heard another Dora line again and opened the door a little wider this time, which led me to realize the obvious: one of the stuffed toys in her bed tonight is her talking Dora doll! Every time Laurel moved in her sleep, she was setting it off.