Minor sex workers and children working in mines is both about children labor and their "free choice" to do it.
You gave a ridiculous example about "what if aliens invade us"?
How is that answering my question?
I was answering the portion concerning capital accumulation, would you like me to answer what I think about the age of consent? What age am I supposed to assume people in some some random drawing are suppose to be?
There is not a definitive Anarcho-Libertarian position on this issue, but it's certainly not the "children are cattle" sort of nonsense you're trying say.