Their relationship would likely become more protective. Bill would be more watchful over Hermione, given her pregnant state. And Hermione might rely more on Bill for emotional support.
A plot might involve a prophecy that states Hermione and Bill must have a child for some greater good. So, they come together to fulfill this prophecy. Along the way, they face many challenges, but eventually, Hermione becomes pregnant. Or perhaps there's a curse on Bill that only Hermione can break, and in the process of breaking it, they form a deep connection that results in pregnancy.
One plot idea could be the challenges they face in the wizarding world due to their unexpected pregnancy. Maybe there are speculations and gossips among the wizarding community. Another could be how they prepare for the arrival of the baby, like choosing a magical nursery and magical baby items. And a third idea might be how they deal with the reactions of their friends and family, some being supportive and others being skeptical.
If they were pregnant in fanfiction, their relationships would likely become more complex. Bill, Charlie and Hermione would probably become more reliant on each other for emotional support. For example, Bill and Charlie, being brothers, might grow closer as they share the experience of impending fatherhood. Hermione, with her intelligence, might offer practical advice to them. And in return, they could offer her protection and a sense of security in this new and potentially scary situation.
One possible plot could be that in an alternate magical universe, a spell goes wrong and causes both Bill and Charlie to experience some of the physical symptoms of pregnancy, while Hermione, being the brilliant witch she is, tries to find a way to reverse the spell. Along the way, they could have humorous exchanges about the situation and learn more about the magic behind such strange occurrences.
In a fanfiction, perhaps after the war, Hermione decides to study some new forms of magic that Bill is an expert in. They start spending a lot of time together in Bill's study. Bill is impressed by Hermione's intelligence and eagerness to learn, and Hermione is drawn to Bill's calm and collected demeanor. Their relationship could develop as they discover they have similar views on how to use magic for the good of the wizarding world, and they become mates in both a magical and romantic sense.
There could be. The Harry Potter fandom is quite large and diverse. Some fans might see potential in a relationship between Bill and Hermione and write fanfictions based on that. It could be an interesting exploration of their personalities and how they might interact in different scenarios.
One great werewolf Bill, mate Hermione fanfiction is 'The Unlikely Bond'. It beautifully explores the relationship between Bill, who is a werewolf in this story, and Hermione. The story delves into their unique connection, with Hermione's intelligence and Bill's werewolf nature creating an interesting dynamic.
It could protect it by clearly defining the rights of fanfiction writers. For example, it might state that as long as they are not making a profit directly from the Hermione fanfiction and are not plagiarizing other works, they are free to write and share it.
They could help Harry by teaching him new spells. Bill might teach him some advanced defensive spells he learned as a curse - breaker. Charlie could show Harry some unique ways to use magic around magical creatures. Hermione would of course be there to ensure Harry studies hard and understands the theory behind the spells.