One possible plotline could be that Draco kidnaps Hermione due to some dark family obligation related to her birth. Maybe there's a prophecy that involves her and his family wants to control the situation. Another could be that he's misinformed about her birth and thinks she's a threat to the wizarding world as he knew it. So, he takes her to figure out the truth.
Their relationship would be full of tension at the start. Draco's act of kidnapping Hermione at birth is a huge violation. But if Draco has a change of heart and decides to help Hermione instead, she might be hesitant but also curious about his motives. They could start to communicate more, and through their conversations, find out that they have common goals, such as fighting against the dark forces in the wizarding world that might have been involved in the initial kidnapping plot. This could lead to a bond forming between them over time.
The potential kidnappers could be a secret society within the wizarding world that has its own agenda. They might believe that Hermione has a special power or connection that could either help or harm their cause, so they took her at birth to control that. It could also be a non - human magical being, like a centaur or a goblin, who thought that Hermione's birth was a sign of something significant in the magical world. They kidnapped her to study her or use her in their own cultural or magical practices. Or perhaps it was a wizard who had a grudge against Hermione's parents and took their child as revenge.
She could be defiant at first. Hermione is a strong - willed character, so she might immediately start trying to escape or use her magic against Draco. She could also try to reason with him, asking him why he's doing this and trying to appeal to his better nature.
One common theme is the unexpected nature of their relationship leading to this moment. It often involves them overcoming their past differences. Another theme could be the challenges they face during the pregnancy, like how the wizarding world reacts to their union.
At first, their relationship would be full of hostility. Hermione would be furious at being kidnapped, and Draco would be his usual haughty self. But as time passes, they might start to see different sides of each other. Draco could see Hermione's intelligence and courage up close, and Hermione might realize that Draco isn't just a one - dimensional bully.
One possible plot twist could be that the kidnappers were actually working for a powerful dark wizard who wanted to use Hermione's intelligence for his own evil plans. Maybe they planned to brainwash her into becoming a powerful weapon against the wizarding world. Another twist could be that Hermione's real family had a dark secret and the kidnapping was an attempt to keep her away from it. For example, her family might have been involved in some sort of ancient dark magic that they didn't want her to discover. Or perhaps the kidnappers thought they were rescuing her from a prophecy that would bring doom to her if she stayed with her birth family.
Well, in fanfiction, anything can happen. Maybe a plot device like a prophecy forces Hermione and Draco together. They might start off hating each other but as they get to know each other better due to the prophecy's demands, they fall in love. And then, with the help of some fictional magic related to fertility in the wizarding world, they could give birth. It's a very common trope in fanfiction to take two unlikely characters and make them a couple with a family.
Yes, it is quite a popular theme. Many fans are intrigued by the idea of Draco and Hermione getting together and having a family. It allows for a lot of creative exploration of their characters in a different light, beyond the initial enmity in the original series. Writers can explore how they overcome their differences and build a life together, which is appealing to many readers.
There are some fanfictions out there. You could try looking on fanfiction.net. Search for the tags 'Draco', 'Hermione' and 'giving birth'. Some stories might be really well - written with interesting plot twists and character developments.