Sherry was born around 1985 or 1986 to Umbrella virologist William Birkin and his research colleague Annette while working at the Arklay Labratory. Due to their intense dedication and passion for their work, Sherry's parents were often absent in her childhood, but loved her deeply.
In 1995, William and Annette were transferred to the underground laboratory just outside of Raccoon City where Birkin completed his work on the G-virus.