Hespera: Children stole the power of ALL the gods! This is very personal, Billy.
Wonder Woman.: Stick to saving the world, kid.
Pedro Peña: I'm gay.
Shazam: Yeah we know bud.
Anthea: Your real superpower is you.
Shazam: You think I know how to fix this, dude, but I really don't.
The Wizard: Billy, anyone can be worthy, if given a chance. Now go fight for your family! Go fight for the world.
Answer: The dinner scene, where Wonder Woman has the head of the Wizard, never happened. There's no indication they knew each other, let alone were friends. In the realm where superheroes actually do exist, there'd really be no reason why she, Superman, who is supposed to know them too, or any other hero wouldn't be there to help. So the only answer would be an unsatisfactory one that sounds pedantic: she didn't help because it's a Shazam movie and not a WW or JL movie. One could say that she and the other heroes were busy with fighting crime/battles in their own city or they didn't know they needed help. She only appears at the end, it seems, to restore the god realm. It's also been said they didn't think Gal Gadot would be available to shoot her cameo scene, so Wonder Woman may not have been in the film because of a scheduling conflict. But to me, if she was meant to be in the film, they would have secured her availability long before shooting.
Bishop73