Gunnery Chief Ashley Madeline Williams is a fictional character from the Mass Effect trilogy. She is a human Alliance Marine who enlisted straight out of high school. She is 25 years old in the first game. Williams is a competent non-commissioned officer. She joins the squad during the first mission, replacing Corporal Richard L. Jenkins (who was killed in action).
She can be met in the first three games: Mass Effect, Mass Effect 2 and Mass Effect 3. More: en.wikipedia.org.