Hi Scott,
I'm with V. I don't know of characters like this, and I'm not sure how easy a haul it would be to get one through. But having said that, what if your MC could *seem* to be stealing, but in the end is actually helping? Especially if she had a nemesis, an older sibling or a non-likeable adult, who tries to catch her in the act, but ends up failing each time (because the MC isn't actually stealing)? Amelia Bedelia is a character who constantly goofs up, but not because she's malicious, but because she just doesn't get it.
Good luck!
Jody