One idea could be a story where they go on an adventure together. Maybe they discover a hidden treasure in an old attic and have to solve a series of puzzles to claim it. It could be filled with their banter and the strong bond of friendship.
A fanfiction could be centered around a music competition. Phil and Lil form a band together. They practice hard, write their own songs. There are rival bands that try to sabotage them, but Phil and Lil's unwavering support for each other helps them shine on stage and they end up winning the competition, strengthening their bond as friends.
Family bond is a major theme. The relationship between the girl and her lil bro is explored, showing how they support and care for each other. Another theme is growth, both individual and as siblings. As they face different situations, they grow as people and their relationship also evolves.
One popular 'girl meets lil bro fanfiction' could be 'The Unexpected Bond'. It's about a girl who suddenly has to take care of her little brother and how their relationship evolves through various challenges. Another one might be 'Growing Up Together' which focuses on their shared experiences as they both grow older. There's also 'Lil Bro's Big Adventure' where the girl and her little brother embark on an exciting journey together.
Well, 'Fish Cheeks' isn't a novel. It could be a piece of creative non-fiction or a memoir perhaps. But it doesn't have the length and structure of a novel.
My favorite is when Little Richard was on tour. He got to a hotel and the elevator was really slow. So he started singing at the top of his lungs in the elevator as if he was on stage. By the time the elevator reached his floor, there were a bunch of people gathered around, thinking there was a concert going on in there. He just stepped out, tipped his hat and said 'Thank you, y'all' with a big smile.
The color flushing her cheeks could signify embarrassment. In many fanfics, a character's flushed cheeks might indicate that they are shy or self - conscious about something that has happened or been said.
Once upon a time, there were two brothers. The big bro always protected the little bro. As they grew up, they realized their feelings for each other were more than just brotherly love. They were afraid at first, but finally decided to be honest with themselves and their family. Their family was shocked at first but gradually accepted them as they saw how much they loved each other.