Amazing Girl is discussed as if she has overly large breasts, but they are revealed to be smaller than expected.
Amazing Girl stuffs her bra.
However, she is later hit with powers that increase her bust size.
She was wearing a sports bra that day.
Amazing Girl's breasts are so large she needs to carry something in front of her to support them.
Alternatively: Amazing Girl uses her figure to gain employment in the sex industry whilst not fighting crime. See Stripperella.
Or: Amazing Girl actually makes use of them in a fight. Nobody ever takes Baron Wasteland seriously again after that.
Amazing Girl's breasts really do defy gravity.
Zig Zagged: Amazing Girl is drawn with huge boobs in the comic, but in The Movie, an actress with smaller breasts is cast. In a promo picture she has fake boobs, but she can't wear the fakes to do her stunts, so many movie scenes don't have them.
Averted: Amazing Girl is depicted as having average, realistically sized breasts.
Enforced: "The people reading our comics are mostly men. Men like women with large breasts. Ergo, give Amazing Girl large breasts and men will like her!"
Lampshaded: "It still sometimes amazes me that I can still fight crime with these!"
"Female superheroes need large breasts. It's essentially a job requirement."
Alternatively: They're fake. Amazing Girl got implants before she started fighting crime so she'd fit in (or pads her bra while she's in costume.)
Amazing Girl intentionally fakes / changes her bust size and exploits it in order to help protect her Secret Identity; not only is her civilian persona a lot less buxom than her superheroic identity, but people who are focusing on her breasts aren't focusing on her face.
Exploited: Amazing Girl attempts to infiltrate Dr. Slaughter's headquarters, but is quickly identified as a superheroine in disguise due to being the only G-cup in sight.
"I don't need unrealistically large breasts to fight crime!"
Amazing Girl gets breast reduction surgery before she starts fighting crime.
"Seriously, outside of a comic book no one has breasts like hers!"
"Superheros that like small breasts must have trouble finding girlfriends."
Conversed: "Amazing Girl's breast size is ludicrously unrealistic!"
Amazing Girl's figure has led to her becoming a figure of derision amongst the superhero community, meaning that she is not taken seriously as a woman or as a crime fighter. It is assumed that because of her breast size she is an airheaded 'slut' and she is often the victim of sexual harassment from other superheroes, whilst simultaneously the subject of jealous gossip.
Alternatively, Amazing Girl's bust gets in the way when she tries to fight crime, and she is plagued by chronic backaches.
However, Amazing Girl is a confident and strong person regardless, is proud of her body and manages to overcome these issues to be a hero.
Alternatively, Amazing Girl's breasts hinder her when she fights crime, but male criminals are too Distracted by the Sexy to escape successfully anyway.
Alternatively (again), Amazing girl's superpower is being large-breasted, as well as the Required Secondary Powers that go along with it (super strength, impeccable balance).