Not really. Cosplaying Violetta wouldn't be a cosplay: she has no costume, and only kids can watch such a show. Disney movies are for both children and adults. Not as Pixar's or Dreamworks, but they have a more complete audience.
And that's the difference between cosplay and costuming. You can't really take a Violetta cosplay to a stage and expect to win. Even if you're a good singer...you should take that to a singing competition, not a cosplay one :/