Knock-knock

Callia has learned how to tell knock-knock jokes. Here are a couple that she made up herself.

Knock-knock.
Who's there?
Peach.
Peach who?
Peach bump.

Knock-knock.
Who's there?
Peach.
Peach who?
Peach in the cow. Ahh! I'm falling!!!

I don't have any guesses as to what they mean, other than that she must not get any of the actual jokes so she thinks none of them make any sense. If she was aiming for something that didn't make any sense, I think she did pretty good.