With Mario's help, I have discovered that my Great-great Grandmother's name was Margaritta Chiaventone. I did a search of surnames in Italy and there were quite a few, mostly centered in the Piedmont region - and that makes sense - My Greatgrandfather was born in San Ponso.
All I can find out about her was that her father's name was Domenico and that he was deceased at the time of my greatgrandfather's birth in 1888
I did find some possible connections on Ancestry - but the dates just don't add up. You veteran researchers - where do I go from here?