The Wind on the Moon

Two sisters are cautioned by their father to be good while he sets off for war, but the two sisters know it is most likely they will be bad no matter how hard they try to be otherwise.

And so they are, mischievous creatures, and they change into kangaroos to solve a problem and get captured into a zoo and help the other animals (who want to) to escape and a judge sends a jury to jail, and the two sisters must talk him into changing his mind and their father is captured and they must help him escape from prison.

Quite a delight.

A 1001 Children's Book You Must Read Before You Grow Up.