Getting instance of an sub object rather than the original's subobject

How do you reference the instance of a subobject, as opposed to the subobject in the original object?

    var o:GameObject = Instantiate(growStick,coord,Quaternion.identity);
    var e:GameObject = o.Find("extender");

For some reason, the e reference always refers to the extender subobject in the original and not the clone.

When I try using: var e:GameObject = o.transform.Find("extender") as GameObject;, I get "NullReferenceException: Object reference not set to an instance of an object"