Nifa was a soldier in the Survey Corps Fourth Squad, under the command of Hange Zoë.
Nifa was relatively of slim build and average height girl with short dark hair that had straight bangs and straight ends. She had bright eyes, was only slightly taller than Levi Ackerman and was usually seen wearing the standard Survey Corps uniform with the usual green hood. When dressed casually, she was seen to wear a filled, loose-fitting, long-sleeved dress with dark boots and a front laced corset at one point.
Nifa appeared to be a loyal person as she was allowed to record the details of Erwin Smith's meeting with Dot Pixis, and was then entrusted to pass the information to others. She acted serious most of the time but was still shocked at how Levi treated Historia. However, she was shown drinking what it can be assumed to be an alcoholic beverage before giving the report.
Appearance: Nifa was relatively of slim build and average height girl with short dark hair that had straight bangs and straight ends. She had bright eyes, was only slightly taller than Levi Ackerman and was usually seen wearing the standard Survey Corps uniform with the usual green hood.
Personality: Nifa appeared to be a loyal person as she was allowed to record the details of Erwin Smith's meeting with Dot Pixis, and was then entrusted to pass the information to others. She acted serious most of the time but was still shocked at how Levi treated Historia.
Nifa in the story: Nifa is among the soldiers who participate in the rescue of the 104th recruits trapped at Utgard Castle. After Hange's squad rescues a group of Survey Corps recruits at Utgard Castle, Nifa is present when they return to Wall Rose. Upon ascending to the top of the Wall, Hange leaves Ymir, who was heavily injured at the castle, in Nifa's care.
How Nifa echoes later: Later in the Battle of Shiganshina, as Erwin Smith begins to lament the dwindling hopes of his dream, Nifa stands among the many fallen Survey Corps comrades in Erwin's mind. When Hange decides to oppose Eren's decimation of the world beyond the Walls, Nifa is one the soldiers Hange remembers when arguing that their fallen comrades would not support such a narrow-minded decision.
Source: Attack on Titan Wiki, available under CC BY-SA 3.0.