Need help with Speak book report... must have read!?

I have to write an essay comparing one of the characters in Speak by Laurie Halse Anderson. Like Melinda, or Rachel, or Heather or Andy... or one of those. I have to compare one of those characters to another fictional character, and explain why they are similar. It should be a popular fictional character, and make sense, like similar situation, or they did something like the same, like Rachel transforming, or heather backstabbing melinda for the Marthas