10 to 12 weeks is the excepted norm for hand reared. so I would not stress just yet.
I have a whiteface pied cockatiel that I have been hand feeding for about 8 weeks and I pulled him out of the nest box when he was two weeks old.His older brother is less than a week older than him and is already weaned and in a new home(I do not sell unweaned babies). I have a bowl in each cage corner and he shows little to no interest in his food.1 bowl of seed,one bowl of pellets,one bowl of fruits and vegetables and one bowl of water along with millet.I am feeding him twice a day in the morning and the afternoon.What else can I do to to speed up weaning time?