Since the proportions have already been nitpicked enough, I'm gonna complain about your pose!

Look at her wrist! While the human wrist can bend back that far, it'd be pretty uncomfortable. I can only really get it that way by pushing my hand back with my other hand. That's like, a right angle, almost an acute angle.
To do a forward-facing peace sign, you'd want to have her elbow bend (elbow pointed down, rather than out), so that her wrist can be bent at a much wider obtuse angle relative to her forearm.
Look at her wrist! While the human wrist can bend back that far, it'd be pretty uncomfortable. I can only really get it that way by pushing my hand back with my other hand. That's like, a right angle, almost an acute angle.
To do a forward-facing peace sign, you'd want to have her elbow bend (elbow pointed down, rather than out), so that her wrist can be bent at a much wider obtuse angle relative to her forearm.
