My guilty pleasure is reverse Robins, but if you keep most of canon intact and only shuffle the order a bit, it basically also turns into reverse Supers. That's exactly where my brain went.
So the timeline would be: Kara lands on Earth first, then Clark, then Jon is born, and finally Kon is created.
I have so many ideas for Jon and Kon's relationship (while still keeping The Death of Superman), because of the angst potential.
The only problem is I've never actually read any Supergirl comics. So I was wondering: if Kara arrived on Earth first, would she end up becoming a superhero anyway? Or would she be more likely to try living a normal life among humans instead?















