I don't really understand what they are asking you to do. If it is financial help, you need to think of your own family first. If you can't afford to help w/out jeopardizing your own family's financial health, you probably shouldn't risk it, no matter how much you'd like to. That, I think is where the line should be drawn.
Are there other resources you can tap into on this woman's behalf? Even though your ex is no longer in the military, maybe you are still in touch w/military member's families who may have helped Afghan civilians in the past? Or maybe there is some sort of organization that helps these poor people w/basic needs and possibly even health care that you can contact? 'Doctors Without Borders' is the first thing that comes to mind but if they can't help, maybe there is some other kind of organization that can?
http://www.doctorswithoutborders.orgIt sounds like a sad situation, but you've already done some nice things for this woman, and maybe you can continue to be supportive in the same sort of way(s) you've already been. But unless you know specifically what they are asking of you, how can you actually know where to draw the line?
Good luck. Just by caring, you've probably already helped this woman more then you realize.
Edit: spelling