One possible reason could be the stress of Harry's fame. His status as 'The Boy Who Lived' might put a lot of pressure on their relationship. Constant media attention and public expectations could lead to arguments and a growing distance between them.
Well, for their children, it would be a very difficult situation. They would have to deal with a broken family, and might experience confusion, sadness, and even anger. Their friends like Ron and Hermione would also be deeply affected. Ron, being Harry's best friend, would be torn between supporting Harry and trying to keep the family together. He might feel guilty if he couldn't prevent the divorce.
Maybe in fanfiction, Ginny discovers that Harry still has some unresolved feelings for Hermione. This could create a rift between them and lead to a divorce. It's not uncommon in fan - created stories to explore complex love triangles that were not fully resolved in the original series.
Well, in fanfic scenarios, the divorce of Harry and Ginny could be a plot device to introduce drama. It might start with a misunderstanding between them. For example, Ginny could be wrongly accused of something and Harry, in his haste, doesn't believe her. As for the Harry - OC part, the OC could be a healer who treats Harry after a difficult battle and they gradually form a bond.
In one scenario, Ginny is cursed during a Quidditch match. The curse makes her forget her love for Harry. Harry tries everything to break the curse but fails. Heartbroken, he divorces her. The OC is an expert in curse - breaking who Harry meets while seeking a solution. She helps him through the tough time and they end up together.
Ginny might support Harry by simply being there for him. In the face of everyone else turning their backs, her presence can be a great comfort. For example, she could sit with him at meals when no one else will.
One possible reason could be miscommunication. Maybe Ginny feels neglected by Harry because he's so caught up in his own heroic deeds and doesn't pay enough attention to her. So she might seek comfort or excitement elsewhere.
There could be many interesting fanfictions on this topic. One idea could be that in this fanfiction, the 'force' might be some sort of magical or emotional force that binds Harry and Ginny even closer during her pregnancy. It could explore how they deal with the impending arrival of their baby while also facing challenges related to this special force.
Ginny might initially be heartbroken. She could retreat into herself, feeling betrayed and confused. In some fanfictions, she may cut off all contact with Harry immediately.