I don't know what you are doing or have tried so far, but I would suggest just make sure her nose is tipped to the right before you cue her. If she is confused to what you are asking her to do, make sure you give her very clear cues.
Because the horse is young, don't try to make the aid 'invisible' to spectators. Be as clear as you can be, so bend the head slightly inwards, clearly lay back the outside leg and don't let the reins go. If she also has this problem without you on her, so when lunging, she might just need a bit more muscle.
Ive had the same problem!! Make sure you are cueing her before you ask her to pick up that lead, by tightening the rain and moving her nose slightly to the right. Also LOTS of practice helps ans she will eventually get it over time!!