Love and relationship growth. Their honeymoon is a time for them to deepen their connection, so a lot of fanfictions focus on how they become even closer and understand each other better.
One popular 'Ron and Hermione honeymoon fanfiction' is 'A Magical Honeymoon' which details their adventures in a secluded magical location. It has beautiful descriptions of the scenery and their relationship growth during this special time.
One possible fanfic could be about them going to a secluded beach. They might spend their days exploring the beach, collecting seashells and having picnics. At night, they could stargaze and talk about their future together, like how many kids they want to have.
They could visit an ancient wizarding library on their honeymoon. Hermione would be in heaven, poring over rare books, and Ron would be supportive, trying to understand her enthusiasm. Maybe they find a book with a spell that creates beautiful light displays, and they use it to have a romantic evening under the stars.
One possible story could be that in these 10 months, Ron and Hermione are on a mission together. They face many challenges that test their relationship. Maybe they have to deal with a dark wizard threat and in the process, their bond deepens as they rely on each other's strengths.
Hermione, on the other hand, could become more vulnerable yet also stronger. She has always been strong - willed, but this experience could break her down initially. However, as she copes with the miscarriage, she might find new depths to her strength. She could become more in tune with her emotions and learn to lean on Ron more, which is a change from her usually independent self. This new dynamic between them would reshape their characters as they support and grow with each other through this difficult time.
Charlie might be a character who has known Hermione for a long time, maybe through some other connections in the wizarding world. He sees Hermione as someone in need of protection from Ron, whether Ron is acting out of his own accord or is being influenced by external forces. In relation to Ron, he is the one who stands against Ron's actions towards Hermione.
Hermione would likely be very angry at first. She is a strong - willed character and being kidnapped would go against all her principles of freedom and rights. She would probably try to reason with Ron immediately, using her logical arguments to make him see how wrong his actions are.
Well, Ron could have developed a more patient side to his personality. He's had experiences that taught him to be more understanding. Hermione may have become more laid - back. Maybe she realized that she was too uptight before. When they reunite, Ron's new - found patience helps him deal with Hermione's still - somewhat - controlling nature. And Hermione's more laid - back attitude allows Ron to feel more at ease around her. It's an interesting dynamic shift that can make for great storytelling in fanfiction.
I'm not a big fan of such dark fanfictions, but you could try looking on fanfiction.net. They have a large collection of Harry Potter fanfictions, and you might be able to find one with that plot there.