The old adage says, “Don’t let the cat out of the bag.” Then again, I believe it refers to the particular “don’t buy a pig in a poke” circumstance. Oh, the good ol’ days when you pass off some rotten cat as a valuable swine and then have a good laugh about the whole thing over your tankard of mead.
But what do you do about this?

She's too cute to punish.

She did put herself in the bag, mind you.