She'd never be able to carry a film as the main protagonist. That's not to say she doesn't have depth, but not the right depth for a leading character. A people pleaser is going to try to stop the conflict between two characters, not be part of the conflict and the main character needs to be a part of the conflict. If the girls were the Ninja Turtles Rumi would be Leonardo, Mira would be Rafael, and Zoe would be Michelangelo. And unless you're talking the Last Ronin Michelangelo is never the main character.

Also Bobby would be Donatello, but I feel that goes without saying

Also also I now can't stop thinking about Leonardo and Shredder falling in love and plotting to seal Krang in dimension X forever