We saw where the batkids would end up if not with Batman, but if that was true who would ended with Bruce as the batfam!
Warning: This is a rushed job, there are probably a lot of mistakes and not all information.
He doesn't end up in Star city but Gotham. He is taken in by Bruce and becomes his sidekick, Speedy. Later, he goes on to form the Titans (with Dick), becomes Arsenal, and having Lyan. Making him the first child of Bruce, also known as Roy Harper Wayne. He doesn't use a bow, but a bow staff that can transform into a variety of weapons. The hero of Bludhaven.
Two years after Roy left, she realized her father was terrible and ran away, ending up in Gotham. Bruce adopted her, and she became the second Speedy. She eventually dies in his care, only to return to life. Slade finds her on the streets, asks the League for a favor, and lobotomizes her so she harbors hatred toward Bruce. She comes back under the name Ravager causing chaos, fights the new Speedy, eventually loses, and ends up in prison. She escapes, forms the Outlaws, returns, and later rejoins the family. Rose Wayne.
Shortly after being created and rejected by Clark and Lex Kon, he ended up in Gotham during No Man's Land. There, he helped out but acted a little too cocky while people were in danger, which got him yelled at by Bruce and Cassie. He was taken in by Selina, whom she emotionally adopted him, and later was adopted by Bruce because he needed an identity and Selina was a criminal. Clark eventually made amends, and Kon began splitting his time between Gotham and Metropolis. Kon fights like a bat and uses his powers more like a gadget. Probably the best super since he doesn't rely on his power. He even sometimes forget he as them.
She moved to Gotham with her mother. She start running into Gotham as "Batgirl". There, she met Cassie, the two of them became good friends, and when Cassie left to train on Themyscira, she took on the Speedy mantle before later passing it on to the next one. But isn't not the end of vigilante for her, she'll later become Batgirl again but this time under Barbara Gordon tutoring. She's very recognisable with her bow.
Diane sends Cassie and her mother to live in Gotham so that Bruce can train Cassie. She will thus become the third Speedy, much against Bruce’s wishes, though she doesn’t really give him a choice. She’ll spend some time in Themyscira to better understand her Amazonian heritage. She then becomes Wonder Girl when Bruce and her mother die and she sets out to find Bruce don't believing he's dead. She’ll keep the title of Wonder Girl after this story and will be officially adopted by Bruce. Cassie Sandsmark Wayne.
During a gang war, Izzie forms the group "We Are Speedy" to help people defend themselves. She catches the attention of Bruce and the other Bats, who decide to train her. Izzie’s parents are Jokerized, and Bruce, seeing her potential, takes her under his wing and decides to train her personally, turning her into a superhero named Lark. Later, her parents wake up, and she goes back to live with them. But she’s still part of the
Lian, Roy's daughter, has always been immersed in his world and decides to take on the mantle of Speedy. She becomes Speedy when Bruce died and Roy is Batman. After that She splits her time between Gotham and Bludhaven, serving as both Batman's Speedy and Arsenal's Speedy. Her father and grandfather. She hangout a lot with Damian and Jon.
Bonus+ Damian Wayne later
