The paucity of information you provided for such early years makes it very difficult since you doi not even say where they lived in Chile or Argentina or wether they arrived married or came single and married here inthe USA. The earliest census on internet is 1855 in Buenos Aires did she live thereor elsewhere.
Did you obtain her death certificate (long form) at www.nyc.gov./html/records/home.html??
I do not do research only refer you to appropriate websites and addresses. Petertimber