hi karisue...let's see what we can do and take one step at a time..two heads are better than one...as they say! luiga marinelli came to the usa am i right? her death certificate may have some info if you know the town which she died in michigan.
she married ernesto pellegrini right? did they marry here or italy? i would begin with death certificates if they died in this country for both of them.
one doc may have info the other doesn't regarding spouse, etc.
i think you need to get a little more info before writing to italy. such as a birth date or something. family certificates are docs naming parents, children dates of birth/death within a household. you write to the ufficio anagrafe (registry office in that town). for marriage birth and death records you write to a different office ufficio della stato civile (civil registration office).
but i'll take you one step at a time when you're ready to do this.