He primarily did this with his sister Mary and his friend Freddy, turning them into Mary Marvel and Captain Marvel Jr., respectively.
Traditionally, Shazam has the ability to share his power with whoever he chooses, often transforming fellow kids into adult superheroes.
Batman News got the tip that older actors may have been cast to play the adult versions of some of the kids in Shazam!
In the New 52 reboot, he turned his entire foster family into superheroes and many of these characters have been cast in Shazam!, so it’s not so crazy to say that they could transform in the movie as well.