My son is getting much better at sharing. He has his toys that no one else can play with of course, but is good at making sure P has something as well. He's best at sharing food though. If he has leftover cereal, P can have some. If there's a banana, B will split it (always making sure P has a plate or bowl to put it on). And lately they've had Christmas Gummy Bears as a treat. If I give B two, he will automatically eat one and give the other to P. I don't even have to tell him to share.