But she was a leader of one Group of the JSA (iirc the more classic one) and was also later a JLA member.
Just based on a little bit of googeling (I know next to nothing about these characters), potential candidates seem for me:
- Owen Mercer/Capatin Boomerang Jr.
- Meena Dhawan/Negative Flash
- Alexa Antigone/Fuerza (a User of the Strength Force)
- Daniel West/Reverse-Flash (he wanted at least to become a Hero in Suicide Squad)