I'm in the army and i have to teach alot of soldiers who are 18 to 28 years old to go against everything they ever knew about being right handed an shoot left because they are left eye dominant. If she shoots right handed her vision will be dramaticly decreased (making the picture blurry) when she tries to use the pins (same for a soldier shooting through an M4 peepsight) she is young go ahead an use a left handed bow, she already knows how to shoot a gun left handed so she isn't exactly left hand useless