Lizzy might be a person who has had a significant impact on the author's life. She could be a neighbor who was always there to help, and over time, the narrator developed deeper feelings for her. It's also possible that she's someone the author met during a trip, and they had a special connection from the start.
The plot of the Lizzy and Diesel novel is full of mystery and adventure. It follows Lizzy and Diesel as they solve complex puzzles and face unexpected challenges.
One of my favorite scenes in Ciel x Lizzy fanfiction is when Lizzy stands up for Ciel in front of others. It shows her loyalty and her growth from a somewhat sheltered girl to someone who can be a protector. Another great scene is when Ciel lets his guard down a little around Lizzy, like sharing a quiet moment in the garden. It's a rare moment of vulnerability for him.
Hard to say for sure. Sometimes authors draw from real-life events, but they might also purely invent the story. Without more background info, it's tough to tell if 'I Love Lizzy' has a real basis.