unity instantiate new prefab as child code example
Example 1: unity create prefab with child
Add the original prefab into the scene, add the new prefab as a child to it,
then drag the original prefab back onto the prefab in the project view (or just
click Apply in the inspector)
Probably want to delete it from the scene after that
Example 2: unity instantiate prefab as child
GameObject go = Instantiate(A, new Vector3 (0,0,0), Quaternion.identity) as GameObject;
go.transform.parent = GameObject.Find("Stage Scroll").transform;