She could be developed as more empathetic. While Cersei was often self - centered and ruthless, her daughter could be shown as having a heart for the common people. For instance, she might secretly help the poor in King's Landing without her family's knowledge.
One great 'Cersei daughter fanfic' could be 'The Daughter of Cersei: A New Path'. It explores the daughter's journey in a world full of political intrigue similar to her mother's but with her own unique choices. Another is 'Cersei's Daughter: Redemption Arc' which shows how she tries to break free from her mother's more negative legacies and make a name for herself in a different way. And 'Daughter of Cersei: Love and Power' which delves into her relationships while also dealing with the power dynamics in the kingdom.
First, you need to define your character. Decide on her personality traits, whether she's more like Cersei or completely different. For example, if she's kind - hearted in contrast to Cersei, that can create a lot of interesting conflicts. Then, think about the setting. Is it the same time period as in the original story? Or a different one? Next, come up with a plot. It could be about her trying to gain power, or maybe finding true love. Don't forget to add some drama and conflict, like her dealing with her mother's enemies or her mother's expectations of her.
She could also be on a quest for power. Inspired by her mother Cersei's thirst for power, she might start her own journey to gain influence. However, she may choose different methods than her mother. Instead of using manipulation and cruelty, she could focus on building alliances through kindness and mutual respect, which would be a huge contrast to the typical Lannister way.
There's also a possibility of her allying with some of the more neutral houses. Houses that were tired of the constant fighting between the big players. Her daughter could offer them stability and protection in exchange for their loyalty. She could present herself as a new hope for a more peaceful Westeros, which might attract these houses to her side.
Their relationship could start off rocky. Yara is a fierce and independent Ironborn, while Ellaria is from Dorne and has her own set of values. But as they face common enemies, like the Lannisters, they start to respect each other's skills. For example, Yara might admire Ellaria's ability to manipulate political situations in Dorne, and Ellaria could respect Yara's leadership on the seas.
She could be different in terms of her morality. While Cersei is often seen as self - serving and ruthless, the OC daughter could be more empathetic and have a stronger sense of justice. Another way is in her approach to power. Cersei grabs power through manipulation and force, but the daughter might strive for power in a more diplomatic and collaborative way. Also, in her relationships. Cersei has a rather tumultuous love life, but the daughter could be more stable and choose her partners more wisely.
One common theme is the struggle for power within the Lannister family dynamic. Since Cersei is so power - hungry, her OC daughter might also be drawn into the power games of King's Landing. Another theme could be the idea of identity. Growing up as a Lannister has its own set of expectations, and the OC daughter may have to figure out who she really is outside of her family's reputation. Also, themes of love and betrayal often come up. She might face situations where she has to choose between loyalty to her family and her own feelings.
One possible storyline could be that Cersei's daughter rebels against her mother's tyrannical ways. She might see the destruction Cersei has caused and decides to take a different path, perhaps allying with the Starks to bring peace to Westeros.
Another plot could be that they meet during a time of great plague in Westeros. They initially suspect each other of being the cause but then realize they need to work together to find a cure. They travel across the land, facing dangerous groups and old enemies. Along the way, they learn about each other's pasts and form a deep bond.