Often, Luna Lovegood can be found in such fanfictions. Her unique and dreamy nature could bring a different dynamic to the harem. Neville Longbottom might also be involved in some way, perhaps as a friend who supports the harem and helps them out in times of need. There could also be some foreign exchange students or magical creatures in human form that end up in the harem for various reasons.
They would probably have a close relationship. As siblings, they'd likely look out for each other. Fleur might be protective of Harry, and Harry would respect and admire his sister. Since Fleur is older and more experienced in the wizarding world in some ways, she could be like a mentor to Harry at times.
Bill Weasley is often included. Since Fleur was originally engaged to Bill, his presence can add some drama or interesting interactions. He might be a bit conflicted at first but eventually come to terms with Fleur's new relationship with Harry. Another character could be Ginny. As Harry's ex - girlfriend, she could have some complex feelings and interactions in the story, perhaps initially being a bit jealous but later becoming a friend to them both.
Fleur and Tonks might start off a bit wary of each other. Fleur, with her proud and somewhat haughty nature, could see Tonks as a bit too brash. But as they both love Harry, they would have to find common ground. They could start sharing stories about Harry's heroic deeds from their different perspectives. Eventually, they would become friends and support each other in the relationship with Harry.
In many fanfics, Fleur is often depicted as strong - willed. She's a Veela, so she has that alluring quality, but she's also smart and not just a pretty face. For example, in some fanfics she uses her Veela charm in a strategic way to get what she wants or to protect others.
In some fanfictions, Harry Potter might help Fleur by using his knowledge of magic. For example, if Fleur is in a dangerous situation during a wizarding tournament task, Harry could share some of his unique insights on how to overcome the magical obstacles, having experienced similar challenges himself.
One common theme is power dynamics. Given that Harry is 'dark' in these fictions, it often explores how his new, perhaps more assertive or even morally ambiguous nature interacts with Fleur's own strong personality. Another theme is loyalty, as they might have to deal with different allegiances within the wizarding world.
Sometimes, it could be the pure - blood supremacists. They might not like the idea of Harry, who is a symbol of the fight against them, being betrothed to Fleur, who is part - Veela. They could try to create problems between them.
It's a rather unique concept for a fanfiction. To find relevant works, you can also try using more general search terms related to the Harry Potter universe and the characters involved. Sometimes, even if the exact 'Harry is Fleur's mother' tag isn't used, the story might still incorporate this strange relationship idea. So, look for stories that play with family relationships and magical elements within the Harry Potter world.
One common theme is the overcoming of cultural differences. Fleur is from Beauxbatons and has a different cultural background compared to Harry. Fanfictions often explore how they bridge this gap.