Handling unexploded ordinance, while dangerous, isn't combat. That's why.
Besides which, "non-combat" isn't the law, only certain specialties, basically those involved in close combat. We have female A-10 pilots. Ask the Saddamites how combat capable they are. (F-16,F-15, B-52, F-14, F/A-18, etc, etc as well of course, but the A-10s get down and dirty, and often come back full of holes, but still flying) We have females crewing Patriot batteries, and flying helicopters. My favorite story concerns a female Air Force type on an AC-130, or maybe it was on an AWACS that was "working" AC-130s, I'm having a senior moment I guess, who would get on the radio and taunt the AlQaida and Talibunnies in Afghanistan. She'd tell them what we were going to do to them, and afterwards asked them how they liked it, assuming there was anyone left with a working radio to hear her. The Northern Alliance guys would get on the same freq and translate. :)
I have to suppose, given recent experience, that had her aircraft been downed and she had been captured her experience would have been a little less "cute".