In the fanfic, their relationship could be tested in many ways. Maybe there are misunderstandings about the pregnancy, like who should take more responsibility or what their future living arrangements should be. Through these challenges, they learn to communicate better. Charlie might become more assertive in expressing her needs and Harry could become more empathetic. This development in their relationship skills would be a major part of their character growth throughout the story.
For Harry, the author can show his vulnerability. He's used to being the hero, but now in this new situation, he has to rely on others more. He might be scared at times, but also determined to see this through for the sake of the baby. Charlie, on the other hand, can be developed as a very supportive partner. He might have to learn quickly about taking care of Harry, like making sure he eats well and gets enough rest. He could also be shown as someone who is protective, not just of Harry but also of the new life they are about to bring into the world.
Leah could start as a somewhat shy and reserved character but become more confident as she takes on the role of a mother - to - be. For instance, she might start standing up for herself and her unborn child against any naysayers or difficult situations.
In this fanfiction, Sam might develop by learning to be more empathetic towards Rachel's experiences during pregnancy. He could start to understand her fears and joys on a deeper level. Rachel could develop by becoming more independent. Maybe she realizes she can't always rely on Sam or others and starts to take charge of her own life and the future of the baby. She could also become more forgiving if Sam makes mistakes along the way, showing her growth as a character.
Harry might start to see Draco in a new light. Initially, he saw Draco as a bully, but as their relationship develops, he discovers Draco's more vulnerable side. For example, Draco may be under a lot of pressure from his family to uphold certain Slytherin values.
In the fanfiction, Hange could start to rely more on Levi, which is a new dynamic for her. This could make Levi feel more needed and important. Meanwhile, Levi might develop his nurturing side, something that was previously hidden. Hange could also develop a new sense of purpose, not just in her work but in creating a loving and stable environment for the baby. Their characters could change and adapt to the new situation of impending parenthood, which would add depth and realism to the story.
Some characters may start as self - centered due to their cheating ways but then develop a sense of remorse. For example, they might realize the pain they've caused to their partner.
Charlie could become more in tune with his emotions. The impending fatherhood makes him realize his own feelings more deeply. He may also become more patient. Sophie might start to see the world from a different perspective. The fact that she is going to be a mother makes her more empathetic towards other mothers and children in the fanfiction world. She may also start to value the simple things in life more as she anticipates the arrival of her baby.
Thor could develop into a more responsible and protective figure. His usual bravado might be tempered with the need to care for Valkyrie and the baby. He might become more in tune with his emotions and less impulsive in battle, as he now has a family to think about.
At the beginning, they would be very cautious. Harry might be constantly worried about how his friends, especially Ron and Hermione, would react. Pansy would be concerned about losing her status among the Slytherins. As the story progresses, they could grow bolder. Maybe they start to take small risks like holding hands in semi - public places at Hogwarts. And towards the end, they might decide to come out publicly, facing whatever consequences come their way.
Hermione would likely become more assertive in her relationship with Charlie. She's used to being in charge of her own life, and now she has to make decisions with someone else. Charlie, on the other hand, might become more open and communicative. He's used to being around dragons, not people all the time. Their relationship would force him to be more social.