How much should a U12 centre-back be allowed to carry the ball?

If the space is there, I want the centre-back to recognise it and use it. A defender carrying forward can commit an opponent, create a spare player in midfield and change the whole picture. Telling them to pass and retreat as soon as they cross halfway can remove a really valuable decision. The reference I’d give is what happens behind the carry. If the centre-back steps in, can another player balance the space they leave? If they lose it, are we completely exposed? That turns the discussion from “defenders shouldn’t go there” into “what does the team need when you go there?” At 9v9, this is a brilliant age for defenders to learn that their role includes starting and joining attacks. I would only restrict it if the player is carrying because they never see teammates, not because they are a defender.