When I first watched this episode, I was all "OMG SHE'S SO PRETTYYYYY!!!" So I scrolled through the massive list of all the ponies in the show and I found her listed as "Lil' Devil/Sarah Palin". >.> Kind of anticlimactic, in my opinion.
I don't think so. I'm pretty sure this is the first episode a pony with her design has ever showed up. Either way, she's an aide or secretary to the Mayor of Ponyville in my head-canon. Ya know, with the politics and how she was always near Mayor Mare whenever she was onscreen.