Sidera is a communications monitor on the Nexus, though it soon becomes apparent that is not all she has been up to. She frequently, using her sister's name and contacts, attempts to assist with life in Heleus by aiding others, including several exiles. She has even released the gene for cats to be produced on the Nexus.
Sid was born on Palaven, her family consisting of Vetra, their father and their mother. Their mother left them very early on and lived on Palaven for the remainder of her life. Their father was a military man and also left the young turians alone pretty early on after not returning from a mission.
With no parents to speak of, Vetra and Sid survived on the only means they could: smuggling. Vetra, being the elder sister, took the role as head of the family and took care of Sid as best she could. Sid and Vetra were introduced into the Andromeda Initiative when the superintendent, Kesh, found their small time smuggling operation and, instead of turning them in, hired them to get her things the Initiative needed to build its projects. After years of running these strange jobs, Vetra asked Kesh what they were for only to be shocked by the Initiative, Let's just say a new start was looking pretty good right about then.