Your result
Italy — Citizenship by Descent
Not eligible
Italian citizenship by descent runs down a direct line — parent, grandparent, and so on back. It does not pass sideways, so an Italian aunt, uncle, cousin or in-law does not open a claim, and neither does a spouse's Italian family. On what you have told us, this route is closed.
Two Italian routes do not depend on ancestry at all. Marriage to an Italian citizen leads to citizenship after two years of legal residence in Italy following the wedding, or three years from the wedding if you live abroad — halved if there are children. Residence on its own leads there after ten years. Both need a B1 Italian certificate, which has been compulsory since 2018 and catches people out.
It is also worth being sure before you accept this. Family stories lose a generation easily, and an ancestor who "came from Italy" may have been born in territory that was Austrian or Yugoslav at the time, which points at another country's rules rather than none at all. If you can name the town, we can tell you whose law was actually running there on the date they were born.