Blake Lively, explains, "Actually, my grandma's brother's name was Blake, and my sister wrote it down when she was reading a family tree. And they said, "If it's a boy, we'll name him Blake, and if it's a girl, we'll name her Blakely." And everybody thought I was going to be a boy, and then I came out and I was a girl. And they had already been calling me Blake for months because they were positive I was going to be a boy. And they had been calling me Blake for so long, they just kept it."

Source: www.radiofree.com