Everything's pretty much already been said. let her play how she's comfortable, and let her transition into keybinding after she's become a better player. Only other thing is if she's playing melee as a clicker you might have her reroll to healer or ranged until she knows the game better. move her target frames down by her action bars if that's where her eyes are focused, and teach her to tab target, you dont have to keybind to learn that.