"Nana" was the name assumed by a Chiss female who was the wife of Syndic Irizi'stal'mustro, core name "Zistalmu," of the Chiss Ascendancy nation's Irizi family. She spent two years as a caregiver of the Ascendancy's Expansionary Defense Fleet for sky-walkers—young Chiss girls who had abilities that helped them navigate the Unknown Regions—before marrying Zistalmu. In 19 BBY, she served as sky-walker Che'ri's temporary caregiver on the Chiss Nightdragon man-of-war Vigilant during a mission to the Vak Combine capital planet of Primea.
Nana served as a caregiver in the Expansionary Defense Fleet of the Chiss Ascendancy (logo pictured)
A Chiss female assuming the name of "Nana" served the Chiss Ascendancy nation's Expansionary Defense Fleet as a caregiver, taking care of sky-walkers—young Chiss girls who possessed abilities that helped them navigate the Unknown Regions—for two years. After serving as a caregiver, Nana married Syndic Irizi'stal'mustro, core name "Zistalmu," of the Ascendancy's Irizi ruling family. In 19 BBY, when Che'ri—the temporary sky-walker of the Chiss Nightdragon man-of-war Vigilant warship—required a caregiver, Zistalmu suggested his wife, allowing himself to gain presence aboard the Vigilant during a mission to extract Ascendancy Senior Captain Mitth'raw'nuruodo ("Thrawn") from the Vak Combine homeworld of Primea, where he had been undercover on a mission.
The Vigilants Commanding officer, Admiral Ar'alani, originally did not want Nana aboard her flagship as it would bring Zistalmu aboard as well, but she agreed to it at the behest of Expansionary Defense Fleet Supreme General Ba'kif. The caregiver insisted that all aboard the starship refer to her as "Nana," much to Ar'alani's annoyance. While the Vigilant secured Thrawn's vessel, Ar'alani asked Che'ri if she was ready to jump to hyperspace. Nana affirmed on the girl's behalf, causing the admiral to ask her directly as she wanted an answer from Che'ri. After Che'ri confirmed she was ready and the Vigilant secured Thrawn's starship, the man-of-war left Primea.
During the mission to Primea, instead of offering her real name, she insisted that all aboard the vessel call her "Nana," which Ar'alani considered an "annoying affectation."
"Nana" appeared in Timothy Zahn's 2020 novel Thrawn Ascendancy: Chaos Rising, the first volume of the The Ascendancy Trilogy.