Check out that baby bump! But mostly the tipoff is the nest she's made, out of her own fur. Also her cravings for pickles and ice cream in the middle of the night.
We suspect Apples the Bunny is the father, since he's a boy, and Little Z took Jingle over to Apples' house for a "Bunny Playdate," where they, "Gave each other piggy back rides." Whoops.