Well, it could be about them rebuilding their lives. Maybe they start a family and deal with the post - war traumas together. They might also be involved in the restoration of Hogwarts, using their magic skills to bring it back to its former glory.
In the fanfic, they could be exploring new magical areas. Since the war is over, they have the freedom to discover things that were previously dangerous. For example, they might go on an adventure to find some long - lost magical artifacts that could help in the betterment of the wizarding world. And of course, their relationship would be at the center of it all, with Ron's humor and Hermione's intelligence complementing each other as they face these new challenges.
Luna Lovegood could be a great supporting character. Her unique perspective on magic and life would add an interesting flavor. Hagrid, of course, would be there, still taking care of the magical creatures at Hogwarts. He could provide a place for Ron and Hermione to relax and get away from the pressures of their new post - war lives. And then there are the younger students at Hogwarts who look up to them. They could be a source of inspiration for Ron and Hermione to make the wizarding world better.
Well, one possibility could be that Ron has been influenced by a dark magic object. This object makes him act out of character and become a threat to Hermione. Severus, having noticed the strange behavior, intervenes. He might use his powerful magic to break the spell on Ron and thus save Hermione from potential harm.
She might be heartbroken. Hermione is a strong - willed character, but being cheated on would surely shatter her. She could initially be in disbelief, given her trust in Ron. Then, she might become angry and start to distance herself from Ron, focusing more on her own studies or other relationships, like her friendship with Sirius.
Their relationship might become stronger as they face the challenges of post - war life together. They have already been through so much during the war, and this shared experience could deepen their bond.
In many fanfics, their relationship develops through shared hardships during the search for Horcruxes. They rely on each other more and more, which deepens their emotional connection.
A good plot could be that Rose discovers she has a unique magical ability that no one in the family has had before. Ron and Hermione are worried but also excited, and Hugo is a bit jealous at first. As they explore this new ability, they face some challenges from other wizarding families who are envious or scared of it.
It can completely change the direction of the story. For example, Ron might become more withdrawn and focus on self - improvement. His friendship with Harry could also be affected as he might be too preoccupied with his broken heart. Or he could start to resent Hermione, leading to a lot of tension between them.
One interesting plot point could be an alternate take on their relationship during the Horcrux hunt. Maybe in the fanfic, they face a particularly difficult Horcrux that tests their bond in a new way, like a Horcrux that plays on their insecurities about each other.
The plot could involve the trio arriving at Avengers Tower in search of something. Perhaps they are looking for a magical artifact that has ended up in this strange new place. Along the way, they interact with the Avengers. Ron might get into some comical situations, like accidentally triggering one of Stark's inventions. Harry could use his skills in combat and leadership, and Hermione would be the one trying to figure out how to bridge the gap between magic and technology. They could end up teaching the Avengers some magic spells while learning about teamwork from the superheroes.
A plot twist could be that Hermione discovers she's having twins instead of one baby. This would double the excitement and also the stress for them. Ron would have to scramble to get twice as many baby supplies.