A possible plot is that fem Percy is sent on a quest that is somehow related to Kronos. Along the way, she discovers secrets about Kronos' past that she can use to her advantage. She might also meet characters who knew Kronos before he became the big bad, and these characters help her in her fight against him. For example, she could find an ancient weapon that was once used against Kronos and learn how to wield it effectively.
One interesting plot could be Fem Kronos trying to manipulate Percy in a more complex way than in the original stories. Maybe she uses her charm as a female figure to deceive him into doing things that would benefit her ultimate goal of ruling. Another plot might involve Percy having to face his own inner demons when dealing with Fem Kronos, as she represents a different kind of threat compared to male Kronos. And there could be a plot where Fem Kronos teams up with some other minor gods or creatures who have grudges against the main Olympian gods, and Percy has to stop their combined forces.
Another plot might be a scenario where Percy tries to reason with Kronos. He could attempt to understand Kronos' motives for wanting to destroy the Olympians and find a compromise. This would be a complex and emotional journey as Percy has to face the being who nearly destroyed his world.
One idea could be that Fem Percy has a unique connection to Kronos. Maybe she can see into his past and uses that knowledge to try and prevent his rise. For example, she discovers a long - forgotten weakness of his from his early days. Another plot could involve Fem Percy being tricked by Kronos into doing his bidding at first, but then realizing his true evil nature and turning against him. This could lead to an intense battle of wills between them.
Luke could also be a prominent character. Since he has a complex relationship with Kronos in the original story, in fanfiction he could play a role in either helping or hindering fem Percy's efforts against Kronos. Nico di Angelo is another possibility. His powers over the dead could be useful in a fight against Kronos, and he might team up with fem Percy for that reason.
One interesting plot could be Percy's internal struggle with his new identity as the child of Kronos. He might battle against the dark urges that come with his heritage while trying to stay true to his friends at Camp Half - Blood. Another plot could involve Percy facing off against the other demigods who see him as a threat due to his relation to Kronos.
One plot idea could be her struggling to hide her true identity within Camp Half - Blood. Since Kronos is a major villain, the other campers might be hostile if they find out. Another idea is her trying to redeem her father's name in some way, perhaps by finding a way to undo some of the harm he caused. A third could be her having a special power due to her heritage that she has to learn to control while also dealing with the stigma of being Kronos' daughter.
A plot could revolve around a mystery that they need to solve. They might start as strangers but gradually become partners in the investigation, uncovering secrets about their world along the way.
One interesting plot could be Fem Hades helping Percy on a quest in the Underworld. Maybe she uses her unique powers as a female version of Hades to guide him through dangerous areas that are usually off - limits to normal demigods.
I'm not sure of a specific title, but in general, these types of fanfictions often explore how being Kronos' daughter would make her an outcast among the other demigods. They might also show her coming to terms with her father's actions and trying to make a name for herself separate from his dark legacy. You could search on popular fanfiction sites using relevant tags like 'fem Percy', 'Kronos' and 'daughter' to find some good reads.
Obviously, Percy Jackson is one of the main characters. He is the demigod hero with his own set of powers and a strong sense of justice. And then there's Fem Kronos. She is a female version of the powerful Titan Kronos. Her character might have different motives and ways of operating compared to the male Kronos we know from the original myths. There could also be other characters like Annabeth, Percy's friend and strategic partner, who might play a role in the fanfiction, either helping Percy against Fem Kronos or getting caught in the middle of their conflict.