From Halopedia, the Halo wiki
Birth-to-Light was a second-form Lifeworker.
She was part of the crew of the explorer ship Audacity during the Librarian's expedition to Path Kethona circa 98,395 BCE. She had worked with the Librarian before the journey, and the Librarian regarded her as capable and experienced. She was the first of the crew to analyze Path Kethona for signs of life by studying the light of the local stars. No evidence of technological civilizations was initially detected, leading her to comment on the satellite galaxy's curious barrenness.
After the crew discovered and explored a local planet inhabited by primitive Forerunner relatives, they returned to the Milky Way galaxy. Birth-to-Light, along with fellow Audacity crew member Chant-to-Green, would remain part of the Librarian's core Lifeworker team for the next 950 years.
List of appearances