The old woman in Liam O'Flaherty's story “The Sniper” appears as the Republican sniper lies on a roof, waiting for a target. As an armored car arrives on the street, the woman comes around the corner and talks with a man who sticks his head out of the car. She is pointing toward the sniper's position, and the sniper recognizes her as an informer. He opens fire, killing both the man in the car and the woman.
This old woman is, first off, symbolic of the dangers and horrors of war. War is deadly, and it can take the lives of even those who appear to be the least affected, like this old woman in her tattered shawl. Before the story's end, she lies dead in a gutter.
The woman is also symbolic of a commitment to one's cause. She knows the danger of being an informer, yet she assumes the role anyway and meets the man in the car. Before this moment, she must have done a good job hiding her allegiance, yet she is clearly committed to the Free Staters, or she would never take the risk of being out in the street and revealing the position of an enemy sniper.
In the sniper's eyes, the woman is a symbol of danger and of his enemy. She knows his position, and she reveals it. She is his enemy, and that's why he kills her without any thought to the fact that she is elderly and a woman. The sniper sees only a dangerous informer who could bring about his death.