@Bronson881 said:

It a nice episode. Loved that fight between Supergirl and Rhea. So Cat Grant knows Kara is Supergirl.

She figured it out last season then they tricked her into thinking kara wasnt

she figured out who the guardian was and he was pretty much covered in armor, Kara/Supergirl is pretty much no mask, only an idiot will not figure it out..

It was a good episode but I thought the "kryptonite blood" thing was unneeded, ham handed, and ultimately self defeating. Of course Cat knows who Supergirl is. The writers in the Arrowverse aren't smart enough to handle secret identities. In all of these shows virtually everyone knows who the heroes are, even all of the villains. I think that is a mistake because it takes away one of the biggest weaknesses that super heroes have. That forces them to make the villains too powerful and causes the heroes to look weak and/or stupid.