Despite casting a number of roles this season which correspond to existing DC comics speedsters including Jesse Quick, we only now have confirmation of a female speedster.
Allison Paige (The Lizzie Bennet Diaries) has been cast as Eliza Harmon aka Trajectory. When a new speedster begins causing chaos around Central City, the Flash gets the blame. Barry and the team have to track her down and figure out why she is causing all this destruction.
Look for Trajectory to burst onto the scene in Episode 2:16.