One of the things I'm curious about is that the Mikes said Supergirl would have a supporting cast. I sort of think that's a mistake, but nothing to be done about it; you need people for the talking.
Since she doesn't know anything about humans that could be darkly funny.
Supporting characters: "Please we don't live in cages!"
Supergirl: "what sort of owner would I be if I let you monkeys wander around uncared for?"
Or maybe an issue where Superman had to explain to a baffled Supergirl why eating human flesh is prohibited.
Sadly I doubt they will go that way....