Either
1. Use sprite.scale to scale the hierarchy manually
or...
2. Use a non-uniform scale on ALL the sprites and their children. Easiest way to do that is to change the z axis of transform.localScale on the entire hierarchy.
Root = 1, 1, 1.0001
Child = 2, 1, 1.0001
Child2 = 1,4, 1.0001
Now you will be able to scale root and as long as the scale is non uniform (i.e. z != x | y) you will be fine.