Thats up to you and your friend to work out. Maybe direct her to the forum so she can see other people's opinions of babying a horse.
Horse's don't need a cuddle buddy, they need a leader. By babying him when he baulks, she is purely reinforcing his behaviour. Horse's learn from the release of pressure. So you put the pressure on to ask him to move, he baulks and rears so you stop putting pressure on and give him a pat. He thinks "GREAT! I did the right thing, when mum waves a whip at me, I just need to stop and rear to remove the pressure". Then the rears get higher, more dangerous and it becomes ingrained in his thought process. Once you teach a horse that it is ok to rear, even just little hops of the front legs, you are setting yourself up for absolute disater.
Personally, I don't think your friend is asking for trouble having a young horse, without even knowing one the the most basic aspects of training.