This Supergirl is amped to unknown levels. What i do know is that she was able to stomp some Lanterns. I can't remember all of her battles offhand, need to go back and look but she is up there. She would wreck Red She Hulk.
Both at normal levels, it would be an amazing fight but Supergirl should be able to eventually win depending on if Red She Hulk doesn't absorb the entire fight.