"nyota" means "star".
That's precisely what Bill Rotsler told her. The meaning is explained fully in "Uhura's Song" by Janet Kagan, working from "ST II Biographies".
Well, we're not dealing with my malleable memory. There were interviews and articles with fans of the day who described how they approached Nichols, Takei and Roddenberry for their "kind permission" to "approve" the choices of first names, but... they all knew the names may one day be overruled (by canon) and Nichols was hardly going to tell Bill Rotsler he had to use Penda because she'd already approved it for use in fanzines.We could be dealing with that legendarily malleable Nichelle Nichols memory in action again, because in more recent interviews she gives the impression that the first time anyone brings up the idea of Uhura's first name is Rostler's inquiry.
In any case, Pocket Books often preferred to avoid fanfic "fanon" where possible. eg. the dropping of Leslie Fish's Andorian lore intended for reference in "The Eyes of the Beholders" and "Metamorphosis" TNG novels.