Script that mimics a child object behavior.

Are you sure that you want to make it be absolutely like child? If a far "parent" object? A little rotation or "parent" may cause a huge movement of "child". But you can make it rotate synchronously around it's own pivot.

 public GameObject ala_parent;
 Vector3 d_rotation, d_position, d_scale;
 
 void Start() {
   d_rotation = Quaternion.FromToRotation(ala_parent.transform.up, transform.up);
   d_position = transfom.position - ala_parent.transform.position;
   p_scale = new Vector3(transfom.localScale.x/ala_parent.transfom.localScale.x, transfom.localScale.y/ala_parent.transfom.localScale.y, transfom.localScale.z/ala_parent.transfom.localScale.z);
 }
 
 void Update() {
   transform.position = ala_parent.transform.position + d_position;
   transform.rotation = d_rotation * ala_parent.transform.rotation;
   transform.localScale = Vector3.Scale(ala_parent.transform.localScale, d_scale);
 }