Flavia - pretty and Roman, but I only like flah-vee-ah, not flay-vee-ah.
Prudence - I think it's cool.
Genevive - looks wrong, Genevieve is okay.
Constance - no.
Juniper - trendy name of the moment, would avoid.
Athena - see Juniper but a bit less trendy right now.
Odette - cool.
Winthorpe - not trying to be rude, but are you joking? It reminds me of "windpipe".
Clementine - fine.
Oceania - no.
Julietta - Juliet is nicer.
Cybil - Sibyl is fine.
They all don't go with Macaulay which is quite dated (formerly trendy) but that wouldn't bother me. I like many names on your list.
I would pick one of these: Prudence, Genevieve, Athena, Flavia, Odette, Clementine, Sibyl.
The contrast between Prudence, Sibyl and Macaulay is huge so if that bothers you I'd pick Genevieve, Athena, Odette, Flavia, Clementine instead.
Suggestions:
Maia
Thalia
Gaia
Persephone
Nina
Calliope
Juliet