I was thinking about Super Sons and all the current super kids. These are the only ones I can think of that would work in this canon.
Damian Wayne: Son of Bruce Wayne and Talia Al Ghul.
Jonathan Samuel White (Jon Kent): Son of Lois Lane and Clark Kent from pre-Flashpoint. Living under aliases because of the other Lois and Clark of this world Jon is just discovering who he is.
Emiko Queen: Daughter of Shado and Robert Queen, half sister of Oliver. She's an archer too.
Maxine Baker: Daughter of Buddy and Ellen Baker.
(Young) Rip Hunter: Well he isn't Rip Hunter yet. Techically this could work two ways: the new world has a young Rip that Booster doesn't know of or pre-Flashpoint Rip from the old world comes over. The mysteries surrounding him haven't been solved and they made a point of saying Booster from Covergence had a ten year old son.
Rani: This one is even a bigger maybe than Rip but something could finally be done with her character. It would be cool if we could see Rip and her forming a bond. Maybe touch on her still being affected by what the Emerald Empress did? Or have her decide to become a superhero?
Milagro Reyes: The sister of Jaime Reyes/Blue Beetle. Fans have wanted her to become a Green Lantern because of her scene with Guy Gardner. In the comics Black Beetle claimed she'd grow up to fight against her brother because of an head injury. Usually Black Beetle tells B.S. although we saw a flash forward. The idea was shaky since Jurgens didn't approve of Black Beetles' portrayal in Blue Beetle. Still the idea of her becoming more than she is has been considered.
That's the only kids I can think of that aren't babies. I have no idea how old some of them are supposed to be. I'd say the first four are more likely to meet up although Jurgens is working on material with Jon and left a lot of plots hanging for Rip Hunter.