So Whitney wins in the end?
She basically does with how things turn out and what she says. Seemed like in spite of being "exposed" she was in control and her plan worked.
sharecould have done with a spoiler alert ahead of the o/p! Short answer - Yes, she does, but it doesn't matter.
Long answer - As her science teacher said, there's always going to be jerks, that doesn't change after high school, and you can either waste your time and your physical and mental energy trying to get revenge or trying to prove them wrong or trying to "beat" them, or you can focus on what you want to do with your life.
Nice case in point that in the end, the a-hole principal is still the principal and will continue to lord it over said science teacher. It makes a refreshing change that they played it this way - I was expecting some cliched scene near the end in which the science teacher gets one over on the principal or finally stands up to him, or better still there'd be some big reveal that the principal was having an affair with Whitney (which would make sense as he seemed to worship her and do everything she commanded) and so is fired and arrested, and the science teacher takes over. It would go against the message he gave earlier though.
And kudos to the writers for an ending in which the bullies "win".
Also gotta love the irony that Jodi and Mindy were "winning" for so long and then got greedy for more and that's when it fell apart and Whitney capitalised. There's a lesson there too.