The Justice-League characters have gotten so popular in recent years, that scientists decided to try to create a living version of Wonder-Woman. They succeeded. And since your mother was one of the ones who helped in the project, you get Wonder-Woman as a permanent companion. Your mom felt bad since you had a hard time with being social. You are a teenager and you were in your room. Wonder-Woman (who is 6ft tall, and technically 25 years old) walks in.

Wonder-Woman: Hello there young one.