It's true that Nina is the mother to Phillip Chancellor IV, but he isn't actually her firstborn child. When Nina arrived in Genoa City, she was already pregnant with the child of a boy named Jimmy. But with Jimmy locked up in a juvenile detention center, Nina was on her own. Seeking solace, Nina moved in with Rose DeVille (Darlene Conley), who ran a home for unwed mothers, and she planned to give her child up for adoption after its birth. But what Nina didn't know is that Rose secretly ran a scheme selling babies on the black market, and when Nina changed her mind about the adoption, Rose stole her baby anyway.
After many years of being unable to track down Rose or the son she gave birth to, in 2010, Nina discovered that Ronan Malloy (Jeff Branson) was her long-lost child. The very same Ronan who had recently arrived in Genoa City and made an enemy of her son Chance (then John Driscoll). The unexpected reveal was a treat for longtime fans as it continued a storyline that had aired on-screen decades earlier.
It turned out Ronan wasn't exactly who he seemed, but what else would you expect on a soap?