Idk about that. She's certainly slower than Superman in combat speed, and she explicitly said Karen was as fast, just not as trained. By feats, I expect the difference is minimal
I'm guessing it is after that since Return of Donna Troy ended after the Flash/WW story and that's the Kara Supergirl outfit so it can't be earlier than 2005I'm not 100% sure, i think it was around that era but before Zoom unlocked Cheetah's speed(i wouldn't bet on it though).