She might also use her skills to her advantage. If she's good at racing, for instance, she could enter races and win, gaining respect that way. This would show the bullies that she's not someone to be trifled with and that she has value in the fanfiction world.
She could stand up for herself. By being assertive and showing that she won't be pushed around easily, she might deter the bullies. For example, using her quick - wittedness to outsmart them in verbal exchanges.
Vanellope could find allies. There might be other characters in the fanfiction who are kind - hearted or also victims of bullying. By teaming up with them, they can support each other and be stronger against the bullies. Maybe they could form a sort of anti - bullying group within the story.