consider a parent object with a script?

I’ve got a problem… I’ve got an empty as a parent from a mesh to rotate this on a local axis. Now I want to select the child via script to setup some modifiers on it.
I guess I need an algorithm to walk through my parent an select the MESH below. Is this possible? Couldn’t found anything in the net yet. :eek:
any ideas?
thanks for your help

PS: The child has no id to select it. (this is a part of a bigger project)

With ‘mt’ as your empty:

child_object = mt.children[0]
arr ='array1', 'ARRAY')