1. One of your students' mothers is in the military. The child tells the class about it and one child says,?

Maybe point out the factual discrepancy between said child's statement and the fact that other child's mother is in fact in the military.

Just ignore its stupidity

YOU don't, because YOU don't have students. That would require being older than 13.

I would tell them the story of   Jessica Lynch........

the real actual story, not the PR BS that Bush put out to the world. 

it would also depend on the age of the children, obviously.....as much of that story is not fit for young ears. 

I would say,  Girls can not be in the army but when you turn 18 your are an adult and can join as an adult woman.