Vanellope V.S. Thatch is the baby sister of Eric Thatch. Thought dead after the shipwreck six years ago, she has lived as the cabin girl of the Queen Ann's Revenge, the ship of the infamous Blackbeard.
Vanellope is an energetic, tomboyish child filled with life and humor. Sadly, years of bullying and being kicked around has left Vanellope with a sour look on life and people, meaning she is often prone to heavy insulting and sassy remarks. Luckily, Vanellope was able to see the goodness in people through the friendship of her brother, Ralph, and Ariel. Though she was often bullied by the crew of the Queen Anne's Revenge, Vanellope was apparently more than happy to attempt making amends, referring to the others as her "fellow pirates", even though they never saw her as one of them. This shows that Vanellope is a very forgiving person. This is also seen during the scene where Eric and Vanellope are reunited with their father at the Fountain. It took no time at all for the young girl to forgive Ralph after the bad-guy admitted he was wrong for what he did. Another example is when Vanellope regains her throne and gladly accepts the citizens of Sugar Rush's apology for tormenting the girl once their memories of her rule were restored.
Vanellope is also incredibly determined, strong-willed, beautiful, and very loving. Even after 6 years of torment and being told she could never be a pirate, let alone pilot a vehicle, the young girl always took the chance to live her dream should a chance come her way. Vanellope's loving ways are best expressed in the scene where Eric takes the water from the Fountain, taking her place as the sacrifice, yet Jack had swapped out the cup with just plain canteen water unknown to anyone. But before that, she stated that her family was more important than her own life in her eyes, as Eric and the others were teh only people to ever show her kindess at all, which meant the world to her.
She also has a twisted sense of humor, notably shown when she kidded her brother into thinking she was going to have him walk the plank.
Once she learned she and her family was married into royalty, she declined to be referred to as a "princess", due to developing a tomboyish attitude, opting instead to be called a president "for democracy's sake".
She's also shown to be a little bit insecure around mature women, such as Ariel, Kida, and Olette at first. Believing their more developed bodies steal the attention of the dumb boys from a cute girl like her.