Well, perhaps the daughter in the fanfiction could be born with a prophecy attached to her, much like Harry had. And she has to figure out how to deal with this prophecy while also coming to terms with being Harry's daughter. She might also form an unlikely alliance with some of the old enemies-turned - friends of her father, like Draco Malfoy, who could act as a mentor of sorts to her in the wizarding world.
One idea could be that Harry discovers he has a daughter from a past life or a time - traveling situation. She might inherit some of his magical abilities in unique ways, like being able to communicate with magical creatures on a deeper level. Another could be that she has to face the same kind of challenges Harry did, but in a different era, and she uses her father's legacy as both a source of strength and pressure.
A possible plot could involve the daughter being sent to a different magical school than Hogwarts. There, she discovers new forms of magic and different cultural aspects of the wizarding world. However, she still has the burden of being Harry's daughter. This could lead to her being targeted by those who either idolize or hate her father. She then has to prove herself not just as Harry's daughter, but as an individual with her own skills and identity.
One idea could be that Harry Potter's daughter discovers she has a unique magical ability that no one in the wizarding world has ever seen before. This could lead her on a journey to understand where it came from and how to control it.
One idea could be that Harry is reborn with all his previous memories intact. He uses this knowledge to change the course of events much earlier. For example, he could start befriending Hermione and Ron in a different way, perhaps by being more upfront about his past experiences and the threats they will face.
A possible plot is that she gets into trouble when some dark wizards mistake her for a key to some powerful dark magic related to Harry and Sirius. So she has to rely on her friends and her own wits to escape and prove that she's not what they think. Also, she could be involved in a time - traveling adventure, where she meets her father and godfather at different points in their lives, which gives her a new perspective on their relationships and her own identity.
A possible plot is that Fem Harry, as Celestia's daughter, has a connection to the stars and constellations. She can draw power from them and use it in her magical battles. She could be on a quest to find a lost celestial artifact that has the power to save both the wizarding world and the celestial realm her mother rules. Along the way, she uncovers secrets about her family and the ancient bond between the two worlds.
Another plot could involve her trying to fit into Asgardian society while still having her strong ties to the wizarding world. She might struggle with the different cultures and values. For instance, Asgardians might not understand her love for magic which is seen as a very different form of power in their world. She would have to find a way to bridge the gap between the two.
One idea could be being reborn as Harry's long - lost twin. You could then have a whole new dynamic where you both share the burden of being the Boy Who Lived, but also have your own unique abilities and personalities. Another plot could be being reborn as a Slytherin who tries to change the house's reputation from the inside. You might start off being shunned by the other Gryffindors and friends of Harry, but slowly prove that not all Slytherins are bad.
One interesting plot could be a character reborn with memories of the future. For example, a minor character who remembers Voldemort's rise and fall and tries to change things in a different way. They might try to prevent certain deaths or change the course of the wizarding wars.
One interesting plot idea could be Harry being reborn into the Katekyo Hitman Reborn world with his magical abilities intact. He could use his magic to create unique weapons or defenses, like using a Patronus charm to protect himself from an enemy's attack. Another idea is that he teams up with Tsuna and his friends to take on a new, powerful enemy that threatens both the magical and mafia worlds. Maybe he teaches them some basic magic spells to give them an edge in battles.
A great plot could be Fem Harry being hunted by vampire hunters who mistake her for a normal vampire. Since she has wizarding skills, she could use magic to outwit them in creative ways. Also, her story could involve finding other hybrids like her. Maybe there are some half - vampire, half - something - else beings out there, and she teams up with them. Regarding her relationship with Klaus, he could be teaching her how to control her vampire side, but at the same time, Fem Harry is trying to keep her wizard identity a secret from the vampire world.
One possible plot idea could be exploring how Harry's new identity as Helas' daughter changes his relationships at Hogwarts. For example, how his friends like Ron and Hermione react to this revelation. Another idea could be the discovery of new magical abilities that come with this heritage, which might help in the fight against Voldemort.