(written from a Production point of view)
Sissy Sessions is an actress who appeared as a background performer in several episodes of Star Trek: The Next Generation. She was identified and named by polaroid continuity photos and call sheets of the episodes and is also listed as Cissy.
In addition to her work as a background performer she was a recurring stand-in and photo double for several guest stars such as Rosalind Chao in the fifth season episodes "Disaster", "Violations", and "Power Play" and for Patti Yasutake in "Ethics". For "Silicon Avatar", she filmed her scenes on Wednesday 7 August 1991 on location at the Golden Oak Ranch and on Thursday 15 August 1991 at Paramount Stage 16. She also filmed additional blue screen scenes for this episode on Monday 26 August 1991 on Paramount Stage 16.
Sessions filmed scenes as transporter operator in scene 9 of the fifth season episode "Cost of Living" but did not appear on screen.