When Nikita infiltrates the bad guy's compound for the first time, she is wearing a beige jacket with a white turtleneck underneath. As the camera cuts back and forth to her, she is shown from the back we can see that she is sometimes wearing what appears to be a black T shirt under the white turtleneck with the hem sticking out, and in other cuts the black garment is gone, the white turtleneck being smooth against her back and no longer showing bulk nor black hem underneath.
When she comes out of the white room, where she talked to Roger, Niktita's make up has completely changed: she is now wearing darker lipstick and darker eyebrows, and her top lip has noticeably been pumped up, as it then looks like it has near doubled in size.
When Nikita comes back from attempting to rescue Kyle---Roger's 5 year old son---she is wearing a different sweater under her coat and on top of her white turtleneck. While out on mission, she was wearing a cropped white jacket with long rabbit fur; when she returns to Section, she is then wearing a longer, beige cardigan instead of the white fur one.
Nikita acts uncharacteristically weak and frightened when Suba is about to have his way with her in bed. This is more of a writer's error: Madeleine just told her that she passed probation. She is more skilled. Yet, she has before been seen taking down men, punching them, she knows martial arts and psychology techniques. Yet, she tries nothing to get away from Suba or take his men down. Even though she is not armed, Nikita has never been written to be meek, weak and defeated.