from The Century Dictionary and Cyclopedia
- Inclosed by fences; fenced in so as to form small fields.
- Like pews in a church: said of the going in hunting, where leaps (as over fences) are frequent, as if over the back of one pew after another with little room for take-offs.
Sorry, no etymologies found.
Hell, I think Junie B. Jones is bad for kids (I think it's patronizing and stewy-pewy cutsie-wootsie besides) but I'm not going to stand in anyone's way of reading it.