I don't think you can: when you absolutely position an element, by definition you take it out of the document flow, so as far as positioning goes that element is no longer a "child" (though it still is semantically). Is there a reason you cannot absolutely position the parent element, instead? (Or for that matter, is absolute positioning really required?)
"Please give us a simple answer, so that we don't have to think, because if we think, we might find answers that don't fit the way we want the world to be."
~ Terry Pratchett in Nation
It doesn't appear you need to absolutely position that div since you are giving it top:0 and left:0 and the div it's directly inside is position:relative. What happens if you just drop the position:absolute? I'm probably missing something obvious, but it appears about the only thing position:absolute is doing for you here is causing the problem you are trying to solve...