I prefer
Ariel, but otherwise it's okay. 3-syllable ideas could be:
Rosalind,
Cassandra,
Betony,
Bethany,
Elinor, Mirabel,
Rosaline,
Cassidy, Megara,
Megaera,
Thalia,
Vivian,
Vivienne,
Winona,
Marian? I'm not sure how well any of those fir with
Isaiah and
Naomi though...