LEAP! 2

You know how Odette has a permanent injury in her leg because of a fire that happened on stage in her last performance? And then how at the end when Rosita told Felicie "Let's set the stage on fire tonight!". I think she knew good an well what happened and that she set the stage on fire so she could be the top ballerina because Odette was top before her. 
And maybe, just MAYBE. Regine Le Haunt, Camille's mother, Helped Rosita set the stage on fire. So once Camille grows older, (at this time she is a baby) Rosita can help her be at the top too, and Odette can't get in the way since she's injured. I also think Regine told Odette that she'd give her a job as a cleaner at her house and let her stay in the place next to hers so she wouldn't have to walk far. Except over time the pay got less and less and Regine started insulting her and making her work harder so she doesn't have any thought of going back to ballet. Or she's working so hard and long she won't have time to have a child to teach to be a ballerina. Hence making Camille, the star of the show.