I still don’t understand why she wasn’t the “TRAITOR” trooper. Finn loses that fight, but Chewie knocks her out of it with his bowcaster. It doesn’t kill her because of the armor, but it definitely knocks her out. Then they meet up again on Starkiller Base and Finn gets the jump on her.
It would have made the rematch in The Last Jedi a little more meaningful. I really wish Rian Johnson hadn’t deleted that scene where Finn almost starts an uprising right there on the Supremacy, and Phasma shuts it down immediately. I know it saved him like 2 minutes in the edit but MAN that would have been great.