First of all, Jekyll & Hyde The Musical was great.
This was a near perfect episode. Melissa Benoist showed what a great actress she is when she got mad at her holo-mom & then again at the end when she was quietly panicking while trying to deny her true identity as she realized that Cat had figured it out.
Lots of good things in this episode like finding out that Martian Manhunter & Superman have already met & this Superman doesn't kill, unlike the movie Superman. Aunt Astra getting dragged into the DEO. Plus all the fighting: her sparing with her sister & fighting her aunt while flying & the Kryptonians attacking Maxwell Lord. all in the day time, so you can see everything.
Now Cat knows so things are going to change are work, I just hope she keeps giving Supergirl good advice.
The only problem was that stupid hypocritical line about "white male privilege" from a white woman with 3 personal shoppers & a private jet who spends more on a haircut than an IT guy's rent. It almost ruined a great episode.