I've always thought
Coco was a spunky nn too. I really like it a lot.
I've never been bound to the theory that nns have to emerge unscathed from the formal name either. But for what it's worth, these seem the most obvious origins:
Colette /
Nicolette /
Nicole,
Cosima,
Octavia,
Consuelo,
Monique,
Cornelia,
Cordelia,
Cora,
Coral,
Coralie,
Victoria,
Callisto,
Leocadia,
Jocasta,
Consolata,
Carole,
Scholastica,
Colleen,
Margot,
Clotilda /
Clothilde,
Rocio (yes, I know there's no "k" sound in it -- it's more a visual thing),
Colombe /
Colombina /
Columbine,
Veronica /
Veronique, Coppelia,
Evdokia ("ev-duh-KEE-uh"),
Constantina,
Kerry,
Cathleen.
There's an Irish girl's name
Sorcha, but I'm not sure how to pronounce it. I think it's "SOR-kuh" and if so,
Coco would make a cute nn for it. But don't quote me on the pronunciation.
There were other names like clio and
Clover that I thought of. But if you're unconventional enough to name a dd
Clio or
Clover you'd pretty much use those as the everyday name, wouldn't you? I just don't see anyone coming up with a nn for those. And
Chloe is obvious, but why alter it? It has such a spunk to it already.
Happy Coco hunting!