I've realized that the little sisters in my books are more or less based on my own. Even the demonic emo type little sisters. Yes, those too lol.
Do I have a lot of demonic emo little sisters in my books? Maybe. They definitely all end up being a little insane. Which just shows how much I think of my own little sister.
Well, my little sisters all end up being between five and ten, which is close to my sister's age. The character is also typically strong willed. Yes, my sister is strong willed. You have no idea. Good thing I am too, or I would lose every fight we get into. But as it is, I win them all. Bwa ha ha.
They actually have more in common with her than I think. So, maybe I do secretly admire and love her, even though I don't really realize it, and she's a violent and annoying sister.