Sometimes Fio pulls names from classical mythology, although she had to change one character's name from "Isis" to "Astrid" when the political scene heated up. And did you notice that Vashti's musical daughters were named "Carmen" and "Micaela" after the leads in Bizet's opera?
Yes, name-wise, Fio is shamelessly derivative--enjoy!
Otherwise, Fio gets her names from baby lists according to year of birth, obituaries, and remembrances of classmates from her elementary-school days. And, for no particular reason, her lawyers are always named Charles.