Stick family

So, why is Son of Gray a female?

It's the study of names people. Don't downvote someone just because you don't understand. In times when a name had actual meaning, 'Grayson' would be the son of a man named 'Gray'. It is seen in other lanuages aswell, such as French; Jeanette is the "ette" or "girl" of a woman named Jean.