I looked at her teeth and said, "Well, there seems to be a bigger gap here than I remember..." I stuck out my finger and touched her bottom teeth one by one and sure enough, the front right tooth moved back and forth under my finger.
"Whoa," I said, "You're going to lose a tooth."
Her face lit up like a beacon. "My first tooth! I have to go tell Jonathan! This is SO COOL."
Now she's walking around with her mouth open and her tongue pressing against her tooth. I'm afraid we'll be swimming in drool soon.
(she just called her dad at work to inform him of the momentous news :)