that is one of my all time favorite concepts that I have maybe a dozen or so head canons for. I think it would be incredible, and I think it’d be something Kara would really struggle with but ultimately desire after a lifetime of secrecy. That’s one of the things I think they really flubbed with the alien registry episode – I wish they had a subplot wherein people on both sides were calling for Supergirl to openly register as a show of faith in it, and have Kara debating whether she has a moral imperative to do something like that. Her standing beside the president during the signing of the act is a pretty empty gesture if she’s not willing to put her name down as well.
Listen I have So Many Feelings about alien Kara Danvers that isn’t intrinsically linked to Supergirl and I am always about to burst