The more well known Nanny is a mutant.
The character subsequently appears in X-Factor #35 (December 1988), #40 (May 1989), The Uncanny X-Men #247-248 (August-September 1989), #265-267 (August-September 1990), Generation X #4 (February 1995), Generation X Holiday Special #1 (February 1998), Slingers #9 (August 1999), and Wolverine: Killing Made Simple #1 (October 2008).
Nanny received an entry in the Official Handbook of the Marvel Universe Update '89 #5.
Nanny and her Orphan-Maker became a pair of would-be saviors of mutant children, with Nanny as the brains and guiding force and Orphan-Maker as the brawn. In her mentally addled perception, Nanny believes that parents of mutant children are evil, especially those who abandon their children, or at the very least incompetent and ill-equipped to properly raise and protect young mutants from danger and exploitation. She and Orphan-Maker travelled the world, searching for young mutants to take care of, murdering their parents to sever any family connections and using her minor telepathic powers to control her new charges. Nanny dubbed these children her "Lost Boys and Girls", after the Lost Boys from the story of Peter Pan; in her psychosis, Nanny had developed a near-obsession with children's tales and nursery rhymes, often quoting passages from them appropriate (in her mind) to the situation at hand.
Nanny’s first major mission was at the State Home for Foundlings in Omaha, Nebraska, in reality a facility where Mister Sinister kept many mutant children for observation and experimentation, including the young Scott Summers, who became the X-Man Cyclops; at the time of Nanny's raid on the Home, Christopher Summers, the son of Scott Summers and Madelyne Pryor, was among the children held there. Nanny sought to "liberate" several of the mutant children into her own custody, with the aid of the Orphan-Maker and some of her "Lost" children, but were opposed by Cyclops and Marvel Girl (Jean Grey), then members of X-Factor, who were there to retrieve Cyclops' son. In the course of their battle, Marvel Girl discovered that two of Nanny's "Lost" children were in fact Gailyn and Joey Bailey, the children of Sara Grey, Marvel Girl’s sister, who had been missing for some time. Thwarted by Cyclops and Marvel Girl, as well as demons in the service of N'astirh (there to acquire Christopher Summers and other mutant children for sacrifice), Nanny fled with her Orphan-Maker and "Lost" children in tow; Marvel Girl was forced to let her niece and nephew go with Nanny, who posed little danger to the children in her care, to pursue the demons who had taken Christopher. This initial appearance of Nanny left the impression to the heroes that she and the Orphan-Maker were robots.
In reality, Nanny deployed a decoy ship containing a Life Model Decoy to impersonate the corpse of Storm in the wreckage. Nanny then regressed Storm's body to that of a child. Storm eventually escaped, but with her memories of her adult life blurred and her childhood persona dominant. With the aid of Gambit, Storm regained her adult memories and defeated Nanny and the Orphan-Maker, sending the cyborg duo and their ship crashing into a swamp. (Storm would later be restored to physical adulthood during the crossover storyline, "The X-Tinction Agenda".)
Nanny reappeared much later in Generation X. In the course of acquiring another "Lost" child, the Orphan-Maker's armor began to malfunction; Nanny determined that his (still unrevealed) mutant power was growing stronger, and she had to create a new armor to contain it. She later sent the Orphan-Maker to protect a deformed child trapped in a schoolhouse by a mob believing him to be a mutant. This brought them into conflict with the Generation X team, who had the same goal. The heroes had to deal with protecting the mob and the boy's parents from the Orphan-Maker's violent methods. After the situation ends badly, with an innocent death, Orphan-Maker escapes in a technologically advanced vehicle disguised as an ice-cream truck.
It is notable that in this appearance, Nanny's egg-shaped battlesuit is shown in pieces outside her base of operations, and Nanny herself appears only in shadow as a vague shape.
Much later, a rebuilt Nanny returned in Uncanny X-Men #347, attacking the X-Men and holding them hostage like before. She was destroyed by Trish Tilby in #349, who (as an ordinary human, could not be detected by Nanny) was able to get close enough to the robot to attack her. Right before she was destroyed, Nanny began to display more advanced weaponry, as she was finally angry with the X-Men.
Another version of Magneto's Nanny appeared in the alternate reality dubbed the Age of Apocalypse. This Nanny was the caretaker of Charles Lehnsherr, the toddler son of that reality's Magneto and Rogue. This Nanny was equipped with retractable offensive weaponry and a defensive capability that let her envelop Charles in a protective cocoon formed from her own body mass; her primary function was to protect the child above all else. She was destroyed while performing this function, and failed to prevent Charles' abduction by agents of Apocalypse.