Some children over a certain age have been granted the right to speak directly to the Judge in their own defense, but for the majority of minors - it's practically automatic that when the medical deems it necessary to do a transfusion, they will call in CPS if the parents object to the procedure and call up a judge to get approval. The severity and time in which the child has also makes a difference. If it's a long draw disease or problem, and the child has the time and opportunity to talk with a judge but for quickly degrading health due to traumatic injury or rapidly active disease - they more then likely will not give the child a chance.