Since I haven't read it, I'm not sure. But likely there is the sister who is the queen. There may also be her family members, like siblings or parents, who could play important roles. And there might be courtiers, advisers, or love interests.
I don't know as I haven't read it. But typically in a love novel set in Paris, there could be a protagonist who is in Paris for some reason, like work or study, and then they meet someone special, who could be another main character.
There could be a mysterious old neighbor. This neighbor might have some knowledge about magic or strange phenomena. When the little sister shrinks, the neighbor could offer some clues or tools to help her return to her normal size. Maybe the neighbor has had a similar experience in the past and can guide the little sister through her ordeal.
The parents would be important characters. They could have different reactions. Maybe the father is more accepting and tries to teach the giantess little sister how to use her new power for good, while the mother is initially worried about how society will view their daughter. Their relationship with the little sister and how they deal with the situation can be a big part of the story.
Since I don't know the exact story, it's hard to say for sure. But presumably, the little sister would be one of the main characters. There might also be other family members like her parents or older siblings involved if it's a family - centric story.
There could also be other characters like her friends or potential love interests. These characters would add more layers to the story. Her friends might support her in her adventures, while a love interest could introduce a romantic sub - plot, making the fanfiction more engaging.
Well, since it's called the'stronger little sister story', the little sister is surely one of the main characters. Maybe there's an antagonist, perhaps a bully or someone who challenges her strength. And there could be a mentor figure as well, someone who helps the little sister understand and develop her strength, like an old wise neighbor or a kind teacher.
Some fanfictions might introduce new characters as friends or allies of the little sister. For example, there could be a street - smart kid who helps the little sister understand the human world better since she's growing up in a rather unusual family. But the main focus always remains on the relationship between the turtles and their little sister.
I'm sorry, I haven't read this novel specifically. But generally, it might be about a sister's story in a world where she has a queen - like status. Maybe it involves her journey to gain power, deal with court politics, and relationships with other characters.
Obviously, Merlin and Arthur are main characters. The little sister, whose name varies in different fanfictions, is also a central figure. There might also be other characters like Guinevere who could interact with the sister in various ways.