Trajectory first appeared in the comics as a villain before reforming herself as a hero and in the comics she got her speed from one of Lex Luthor's projects.
Now in the second season of the Flash she will start off as a villain for Barry and his crew to deal with and apprehend for framing him on her series debut but sometime after that episode and before The Flash's final confrontation with Zoom in the season's three remaining episodes she will team up with him against the hostile speed demon from Earth 2 because Zoom isn't just targeting the Flash. He's targeting anyone connected to the Speed Force and robbing them of their speed and since Trajectory has super speed just like the Flash that makes her a target to Zoom as well and with Zoom destined to be the only fastest man alive there is no way he would team up with or work with any other Speedster even if they oppose the Flash. So clearly even if Barry does catch Eliza it would be best to lock her up in the pipeline at star labs instead of handing her over to the authorities and hold on clearing his name until he deals with the King Shark again because if he hands her over to the cops Zoom will eventually approach her and steal her powers from her which will make him more powerful and too powerful for Flash to stop and protect his allies from so hopefully once they catch her they will hold her in a cell in the Star Labs pipeline and have her redeemed as an ally and member of team Flash before the final battle with Zoom approaches after when it comes to dealing with the most powerful enemies and toughest situations, heroes do have to make tough decisions and deal with the most unbarable sacrifices and since Barry is dealing with an enemy much more powerful than the reverse flash he is sure to hold off on clearing him name until after the threat has been dealt with because saving and protecting innocent lives is more important than one's personal feelings
Surely last season Barry tried his best to pursuade Leonard Snart aka Captain Cold to help hijm take down the Reverse Flash but double crossed him over such lack of heart because he wanted to get even with the Flash by humiliating him and Dr. Light backed out on helping him catch Zoom because she was scared of him. But once it comes to someone like Trajectory, Barry is sure to try convincing one of his enemies into helping him deal with another not just for his sake but also for her own because when it comes to a hostile and volatile speed demon like Zoom, she won't have much of a choice but to help the Scarlet Speedster stop him. Plus look at the bright side, with her being redeem as a member of team Flash with just the right push of conviction even if he has to share his secret identity to her, she would make a great ally to Barry and his only hope of stopping Zoom from getting away with his ambitions and keeping him from targeting anyone close to them including their allies. To find out if Trajectory team up with Flash against Zoom in season 2 finale, stay tuned for more new episodes coming in the next 5 weeks to find out and be ready to see Batman Vs Superman Dawn of Justice on March 25th.