I'm not sure of specific fanfictions on this topic. You can try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own. Just use the keywords 'lily sister marries severus' in their search bars, and you may find some interesting stories.
One possible plotline could be that the sister of Lily, initially having some sort of enmity or misunderstanding with Severus, gradually discovers his true self and falls in love. Another could be a more arranged - marriage - type situation where for some reason, they are forced to marry and then develop feelings over time.
One popular Severus Lily fanfiction is 'All The Young Dudes'. It delves deep into their relationship, exploring the complex emotions between Severus and Lily. It shows how their friendship evolved over time and how Severus's love for Lily was both a strength and a source of his pain.
Another theme is redemption. Severus is often seen as a character who is trying to redeem himself through his love for Lily. His actions, whether good or bad, are sometimes motivated by his love for her and his desire to make up for past mistakes.
In the original setting of Harry Potter, Lily married James Potter, but not Snape. However, if Snape were to marry Lily, the whole story would change dramatically. For one thing, Snape's personality might have become much milder. His love for Lily was deep and persistent. If Lily became his wife, the loneliness and indifference in his heart might be resolved by love. When Voldemort first rose and threatened Lily's life, Snape might not need to protect her as a spy, because he could directly protect Lily under his wings. For Harry Potter, his upbringing would be very different. He would probably have grown up in a family full of Potionology knowledge, because Snape was an expert. Moreover, Harry might receive a more direct magical education from Snape, and his magical abilities might develop further in different directions. Things would change at Hogwarts. Snape might not become Harry's "troublemaker" at school, and the relationship between Slytherin and Gryffindor within the school might be eased by Snape and Lily's union. Questions such as the Wizarding world's attitude towards the offspring of Muggle-born wizards (Lily was Muggle-born) and half-bloods (Snape was half-blood) would also become new story elements. However, this was only an imagination based on a hypothesis, which was very different from the original story. Harry Potter and the Goblet of Fire was not enough. Everyone, please click to read the novel!
Well, I've read a fanfiction named 'Lily and Severus: The Forgotten Love'. It presents a unique take on their relationship. It begins with Lily finding an old diary of Severus which contains his deepest thoughts and feelings for her. As she reads through it, she starts to question her own feelings towards him. This story is full of emotional turmoil and self - discovery for both characters. There are also other great ones out there, but these are some of the ones that stand out in the 'lily falls in love with severus' genre of fanfiction.
One popular lily and severus lemon fanfiction is 'The Forbidden Love'. It delves deep into their complex relationship, exploring the unspoken desires between them. The story is well - written, with vivid descriptions of their emotions.
There's a fanfiction called 'Snape and Lily: The Untold Story'. It gives a lot of backstory to their relationship that was not fully explored in the original books. It shows how they first met, their early interactions, and how Snape's feelings for her began. 'In the Shadow of Lily's Love' is another good one. It focuses on Snape's life in the shadow of his love for Lily, how he feels like he can never be good enough for her, and how this feeling affects his actions. 'Lily's Love: Snape's Salvation' is also worth reading as it explores how Snape's love for Lily could potentially be his salvation from his dark path.
The main characters are clearly Lily and Severus. Lily is often portrayed as a kind - hearted and strong - willed character. Severus, on the other hand, is usually depicted as complex, with his own insecurities and hidden depths.
In many fanfictions, Lily might be jealous of Hermione and Severus' relationship because she has her own complex history with Severus. Maybe she feels that Hermione has something she once desired, like Severus' friendship or a deeper connection. It could also be that Lily is jealous of how Hermione is able to interact with Severus in a way she never got to in the original story.
Good ones often have strong character development. For example, they show how Severus' complex personality and his love for Lily interact. They also usually have a well - crafted plot that keeps you hooked.