I wanted to add, for posterity, that Ellie has new a catchphrase. Whenever she accomplishes some kind of physical feat, or uses the potty, or just leaves a room she says, "Cock a DOODLE." As in, "Mom, look at my painting. Cock a DOODLE." Or, "Jimmy, let's run! Cock a DOODLE."
Just now, she walked past my laptop as I was posting those pictures and said to herself, "Heh. That's funny, Ellie. Cock a DOODLE."