Relative MovieClip control help

I have 2 MovieClips inside a parent MovieClip and cannot control one from the otherā€¦ :frowning:
The following do NOT work when called from Child 1:

parent.child2_mc.gotoAndPlay("Start");
parent.child2_mc.alpha = 0;

I can get the name, etc, of the parent MovieClip by using:

parent.name

But I cannot control anything sitting inside the parentā€¦