Not Fast Enough

After reading Wally West abuse stories I really wanted to do my own but as always I had to add a twist.
Scarlett West is five years younger than her brother. When he made the experiment that gave him his powers she got caught in it too. Scarlett was five years old when she became a speedster and although she didn't become a hero at first she is one now. Her name is Messenger and although by looking at her you'd think she was the strongest person ever, she is broken beyond repair. Will anyone figure out what their father is doing before its to late? Or will the two speedsters meet their demise?
Some Spitfire. Justice Grayson because I can. I do not own the characters or the pictures. I only own Justice and Scarlett.