I love
Esperanza.
Nancy is cute and I can see it as a nn for
Esperanza. Then again, I can see Boogaboo as a nn for
Esperanza too, so I may not have the same disciplined approach to nns that you do.
I just did a google search and Esperance is a town in Australia. But it's not a word in French, unless i'm really, really rusty. The French word for hope is "espoir," not "esperance." (If I'm wrong on that someone please correct me.)
Traditionally,
Nancy is a nn for
Anne /
Nan. Did you consider those options (
Anna,
Hannah,
Nan, Anzia, etc.) Other thoughts:
Frances /
Francisca,
Susanne /
Suzanne,
Anastasia /
Nastya?
Not that you asked, but I adore
Constanza. :-)