I would say that every main character I write (and often the supporting ones, too!) have a bit of me and my life experience in them. In my novels, I tend to write protagonists with strong passions—like Henna’s for gardening in The Girl from Earth’s End, and Gladys’s for food in the All Four Stars books—and heavy responsibilities, like Jean has in The Great Hibernation. It was easy for me to draw on my own middle-grade memories to write these characters, since I was a strongly driven (and also often anxious) young person, too.
But I do change plenty of details. I was not a young chef or foodie like Gladys. I was actually a very picky eater, much more like her friend Parm! I based the two dishes Parm eats in All Four Stars (cereal with milk and plain spaghetti) on the two dishes I ate all the time from around age 4 to age 16. (I did become interested in eating new foods and cooking when I was a little older–you can read some of that story here.) In The Girl from Earth’s End, I channeled my lifelong dissatisfaction with gender binaries into the character of P. And I’ve also drawn on people I’ve known in real life to help create supporting characters. Charissa in the Stars books is an amalgam of a few people I grew up with. And for Lora in The Girl from Earth’s End, I drew inspiration from my mom, who used a wheelchair.
With all of that said, I’ve only ever plucked one character straight from real life. Gladys’s Aunt Lydia in the Stars books is very closely based on my own Aunt Judy, who loves scarves and flowing clothes, made up complicated nicknames for me when I was a kid, and still is a huge foodie.