Continuity mistake: On the bridge, when Freddy grabs both cars and stops them from falling down, the driver on the left pops his head out the window, then back in, and then he pops it out again. A mere frame later his head is inside and his body is in a different position with both hands on the wheel.
Continuity mistake: When Shazam is at the shrink, the way his cape lies under his body, plus how far it is extended up to, changes between shots.
Revealing mistake: During the havoc at the museum, a visitor jumps headfirst into a stone column that falls apart. The volute falls to the ground and bounces around, revealing it's a prop.
Continuity mistake: When Shazam is checking the Thesaurus, he holds the phone with one hand. Shot changes and he suddenly holds it with both hands.
Continuity mistake: After Shazam has broken several bottles, he talks with a couple of guys and a breeze starts blowing, knocking out a brown bottle behind him. A shot later, the bottle is suddenly standing up again. This swaps back and forth a couple of times. (02:01:00)
Continuity mistake: When the Wizard shows up during dinner, he takes his glasses off and extends his arms. From the opposite angle, they're lowered.
Continuity mistake: When Billy sits down to dinner, he is looking to our right. For a brief close-up shot, he is looking at our left until the shot swaps back to the previous angle.
Continuity mistake: When the family is having dinner, Mary reaches for the serving spoon. Shot changes and her hand is away, and she is reaching for the spoon again.
Continuity mistake: In the parking lot, Anthea confronts the dragon while all the cops run away past her, leaving her alone, as seen in the wide angle. In the close-up, a bunch of cops suddenly appear out of nowhere, running away and passing next to her again.
Continuity mistake: In the parking lot, when Anthea tries to stop the dragon, she extends both arms and hands. Then, she turns her left hand around slowly. But from the opposite angle, both hands are still in the previous position, and she is turning her left hand around again. (01:32:13)
Continuity mistake: After the dome has been built, when the parents watch the news, there's a shot from behind Rosa where her arms are lowered. Cut to a front shot and they're raised. Then she lowers them, cut to a new angle, and they're raised again only to lower them a second later.
Continuity mistake: At the junkyard, Freddy tosses the golden apple at Shazam, who then stands behind a car, by the driver's side. A shot later, he's suddenly three meters to the right of the car.
Continuity mistake: When the parents are woken up by the noise, Rosa rises and the sheets are not covering her chest. A shot later they are. (01:12:00)
Continuity mistake: When Darla arrives home with the kitten, the position of her left hand differs between the close-up and the following shot.
Continuity mistake: When Mary is bringing people safely on the bridge, not only are they not continuous between shots, but a paramedic suddenly appears behind the ambulance on the right.
Continuity mistake: Before Super Hero Darla arrives at the yellow car, the co-pilot is looking behind her. An instant cut later, she is looking ahead.
Continuity mistake: On the bridge, when Super Hero Darla saves the kittens, on the first shot there are three kittens. A black one with blue eyes and white fur inside his big pointy ears is meowing. A shot later, the two brown kittens have vanished, the black kitten has turned 90ยบ (note the handles of the basket), plus - drum roll - it's a totally different kitten: grey eyes, smaller ears, and full black fur in his ears.
Continuity mistake: When Billy's mum tells him she loves him, she places both hands around his face. Then lowers them and places her right hand on his cheek. From the opposite angle her hand is gone.
Continuity mistake: When Freddie confronts the dragon, he puts his hand on Anthea's back. A shot later, his arm is surrounding her neck, and his hand is resting on her chest.
Continuity mistake: Before Shazam resuscitates Hespera, the way her hair lies on the ground changes between shots. Also, an object behind (a strap or similar) also changes shape and distance between shots.
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