Delta was brought up mostly by Ember until she was about fourteen and then by Jim after the former disappeared into the ether or something. Although she does not have an official position at the clinic, she tends to work in technical support, security and occasionally transport.
Delta is sardonic and rather 'uncough' (as a man like Harrison might say), but she is also very loyal and has a strong moral compass. She is less unshakable than Jim (nearly everybody is) but still has something of a 'seen-it-all' mentality.
Has a mentor-student and slight father-daughter relationship with Jim.