Since we're in hiatus, I wanted to share a relatively low stakes theory (well, at least compared to what we're usually theorizing about) just to pass the time while we wait for season 2b.

To make it so Luz and Vee can both exist in the human realm as separate people, Luz will claim a "Parent Trap" type situation happened when she went to camp. She'll claim she discovered her "long lost twin" just before she left, and they decided to swap places to see how the other lives. She claims that after many wacky adventures, they were found out and Vee chose to live with her and Camilla, and that's why there's now suddenly an identical version of Luz seemingly from nowhere.

Is it the best idea? No. Is it one Luz would probably come up with and then somehow sell regardless of the many holes in the story? Probably.