Although she has yet to make an actual movie or live TV appearance, the closest thing is in the Family Reunion series (issues #4-7) of The Muppet Show comic book, now published by Marvel Comics (formerly by the Boom! Kids subdivision of Boom! Studios), written by Roger Langridge and drawn by Amy Mebberson:
http://muppet.wikia.com/wiki/The_Muppet_Show_Comic_Book:_Family_Reunion
In that series, Skeeter's appearance resembles Skeeter 2 B's and Skeeter Muppet's avatars.
My local library has a compilation book containing issues 4-7, which features a Muppet Labs skit that spoofs a bit of "Bohemian Rhapsody", as Bunsen has developed an invention which helps to track distant relatives, which Beaker helps test out.
Miss Piggy's not-too-bright nephews, Andy and Randy (from Muppets Tonight), come over for a visit; they're apparently even dumber than Link Hogthrob, but not as conceited....
Fozzie's mother comes for a visit, accompanied by Dora, an old childhood friend of Fozzie, who is rather nervous since it's been quite a while since he's seen her....