Levi's backstory

My theory

My theory on Levi's backstory

I believe that Levi had a brother. Think about it, his mother was a
prostitute, making it much easier to have more then one child. Also his backstory could allow Kenny to train two boys. I say that his brother was chased out of town by a gang of some kind. He forgot how to get back and stayed in were he was stuck, living in the street. Levi and Kenny wouldn't talk about him so they didn't have bad memories. Levi stayed closed off, not trying to get to emotionally attached to people. He meet Isabel and Furlan, and when they left he felt the same emotions. He sealed himself off more, but meet Petra. He feel in love with her and she feel in love with him. But once she was killed by the female titan, he felt like he could never trust anyone else ever again. So where on the streets is Levi's brother with little to no memory of his brother and uncle.