I suppose you could traverse the node and rearrange the layers.
Why not just give your ball a high order to begin with? That way when the layers are added they are behind still
addchild(something else, 1);
addchild(ball, 99); // ball is on top
addchild(something new, 2);
addchild(something new again, 3); // both of these would be behind the ball.
I do this all the time and have hundreds of sprites on my screen and a few different layers and HUDS as well.