Percy would use his combat skills. He has a lot of experience in fighting monsters, so if any threats come near his daughter, he'd be ready to fight them off with his sword. He'd also use his strategic thinking to outwit enemies.
He'd probably use his powers over water. He could create barriers of water to keep his daughter safe, or use water currents to move her away from danger quickly. He might also be able to sense danger through the water, like if an enemy was approaching through a body of water nearby.
Perhaps it's an old acquaintance from Percy's past who he reconnects with after leaving camp. They fall in love and she becomes the mother of his daughter.
Well, if Percy was the daughter of Artemis, she'd likely be more in tune with nature. The original Percy was more associated with the sea, but this new Percy would have a stronger connection to the forests and wild animals. She might also be more reserved and independent, like Artemis. Artemis values her solitude and freedom, and Percy as her daughter might inherit those traits, being less likely to rely on a big group of friends compared to the original Percy.
She'd likely be extremely powerful. Since Zeus is the king of the gods, she'd probably inherit a great deal of his power over lightning. She could also have some control over the sky, like being able to create storms or clear skies at will.
She could be a completely new character created just for this fanfiction. Maybe she's a normal human girl who Percy discovers has a connection to the world of the gods in some way.
They might become more protective. Since they are dreaming of having a daughter, they would start to think about all the potential dangers she could face. Their relationship could grow deeper as they bond over their shared hopes and fears for their future child.
Dean protects his daughter by being vigilant. He always keeps an eye out for any supernatural threats that might come her way. For example, he wards their home to keep out demons and other evil entities.
The mother could also be a completely new character created specifically for this fanfiction. She might be from a different realm or have some special powers. And her relationship with Percy could be a complex one, filled with secrets and misunderstandings that led to the situation of having a secret daughter.
There could be various interpretations of Percy's dream about his daughter Kelly in fanfiction. Maybe in the fanfic, this dream is a premonition of something important related to Kelly's future, like a special power she will develop or a great adventure she'll embark on.
She could be the daughter of a minor god that has been forgotten or shunned. For example, the daughter of Hecate's lesser - known cousin who has some magic abilities but no real place in the demigod world until Percy takes her in.
Percy has his water - based powers from Poseidon. In contrast, as Hestia's daughter, she would have powers related to fire and the hearth. Her powers would be more about warmth, protection, and stability. While Percy can control the seas and use water for offense and defense, she could use fire to purify, heal, and create barriers. For example, she might be able to heal wounds by applying a warm, gentle fire. Her powers would be less about brute force like Percy's in battles but more about maintaining balance and harmony, like her mother's role in the pantheon.