The pic of Superman in his T-Shirt and jeans uniform shows that Helena and Karen wound up on the Nu52 Earth.
It's funny, I keep calling it Earth 1, the Nu52 Earth... I wonder if it is... has that been confirmed? Which I'm sure it will be, or at least they don't want to confirm it, because then it would only feed the idea that they can "go back."
Do the people on Earth 1 know about the other Earth's yet? Probably not. But...