I pass this along for what it is worth. I have a lot of good friends, both left and right, and we share things back and forth. I liked this because it reinforces my biases of the kind of citizen soldiers who keep this country safe. Like a lot of things on the Internet, however, they arrive without sourcing. So in this, take this for what it is.
This Internet picture is of a 19-year-old ex-cheerleader (now an Air Force Security Forces Sniper). According to the note, she was watching a road that led to a NATO military base when she observed a man digging by the road. She engaged the target (meaning she shot him). Turned out he was a bomb maker for the Taliban and he was burying an IED that was to be detonated when a U.S. patrol walked by 30 minutes later. It would have certainly killed and wounded several soldiers. The interesting fact of this story is the shot was measured at 725 yards. She shot him as he was bent over burying the bomb. The shot went through his butt and into the bomb which detonated; he was blown to pieces. The Air Force made a motivational poster of her.
Read this Snopes article for more about this poster.