From Janet Mayo, a close friend of Susan Stewart:

Susan Stewart passed away May 6, 2014 at the age of 60 after a brief illness. She is survived by her partner of 38 years Mark White of Spring TX, her sister Cindy Stewart Thompson, a nephew James Thompson, both of Amarillo TX, a sister-in-law Elaine Stewart, nephew Austin and niece Kate Stewart of Fredericksburg TX. She was preceded in death by her parents Dorothy and Frank Stewart, and her brother Dr. Tim Stewart.