Who is Dr. Halsey from The Fall of Reach and what is their importance?

Dr. Halsey is a civilian specialist, she is working on a mission with the military, the USNC. Halsey is described as having very pale skin, dark hair, and blue eyes. Lieutenant Keyes thinks of her as a striking woman. Over the course of the novel, however, she ages significantly, and her dark hair turns gray.

Dr. Halsey is working with the military to create super-soldiers. She is genetically augmenting the children she chooses and abducts from their lives. She uses the augmentation process to create soldiers that are tougher, faster, and more intelligent than the average human soldier. This concept is intended to help the humans win the war against the aliens.