In this fanfiction, Draco's character could be developed through his struggle with his past actions and reputation. The pregnancy forces him to face his new role as a father - to - be. He has to learn to be responsible and caring, which is a big change from his previous cold - hearted self. Ginny, on the other hand, can be developed as she deals with the judgment from others. Her relationship with Draco might make her more understanding of those who were once her enemies, and she can grow in her ability to forgive and move forward.
It's possible that such a fanfiction exists in the huge world of 'Harry Potter' fanfiction. But it might not be a very common or mainstream idea. In the original series, Draco and Ginny are from opposing sides and have different relationships with other characters. So, a fanfiction with this plot would need to do a lot of work to make the story believable and interesting, perhaps by reimagining the characters' personalities and the overall story arc in a significant way.
In the fanfiction, Ginny could be developed by exploring her magical abilities further in relation to Dudley. For example, she could use her magic to show Dudley the beauty of the wizarding world, which in turn makes her more confident in her own identity. Dudley's character can be developed by having him face his own insecurities. He realizes that Ginny is different from what he thought wizards were like, and this makes him question his own upbringing and beliefs.
For the mother character, you can show her growth from shock at the news to determination to bring all the babies into the world safely. She could start as a timid person but become strong and assertive. The father could be developed by showing his support system for the mother, like taking on extra jobs to afford the upcoming expenses. He might also have his own fears but hides them to be strong for his family.
Ginny might first be in shock and denial. But then she could draw on her Gryffindor courage. She would probably turn to her family for support. The Weasleys are a close - knit family, and they would surely rally around her, providing emotional and practical help.
You can try looking on fanfiction websites such as Archive of Our Own (AO3). It has a vast collection of fanfictions, and you can search for 'Draco and Ginny pregnant' in the search bar. There are likely to be many stories there.
In developing these characters, we can show Cho's jealousy in different ways. She might be passive - aggressive at first, like making snide remarks about Ginny. This would show her immaturity. Harry can be developed by having him be patient with Cho, which shows his good nature. But also, he should be shown as being very protective of Ginny. Ginny could be developed by having her reach out to Cho in a friendly way, trying to understand her jealousy. This would show Ginny's big - heartedness and could lead to Cho's character development as she realizes Ginny isn't a threat and starts to work on her own self - worth.
For Draco, you can show his growth from his former self. He could be overprotective of the baby due to his past experiences, always fearing that the baby might face the same prejudices he did. With Hermione, her intelligence could be passed on to the baby in cute ways, like she starts teaching the baby simple spells very early. And as a couple, they can develop by learning to trust each other more in parenting decisions.
Kiba could be developed by showing his more responsible side. Since he's used to being a bit of a wild ninja with Akamaru, now he has to think about the safety and future of his unborn child. Ino can be developed as she becomes more nurturing. Maybe she starts to use her mind - reading ability in a new way, like sensing the baby's emotions in the womb.
For Blaise, you could explore his loyalty to his friends further. Maybe he has to choose between his loyalty to Draco and Theo and doing what's right when it comes to Hermione. For Draco, show his growth from his prejudiced ways. His interactions with Hermione could be a catalyst for that. Theo can be developed by showing his insecurities and how he overcomes them through his friendships. Hermione can learn more about the Slytherin side of things and become more empathetic towards them.
Ginny could respond by standing up to Draco immediately. She's a strong - willed witch, so she might hex him back in retaliation for the physical harm. This would show that she won't take any nonsense from him and is willing to defend herself.