There were many things my maternal grandmother (see Ronzoni post) didn't like to talk about. One of them was that her mother (Brigida) had remarried after her husband (Carmine) died.
Both Carmine and Brigida were Italian immigrants. They were married in San Salvatore Telesino, Benevento, Campania, Italy in 1904 just before they immigrated to New York.
I have had difficulty finding information about their deaths on Ancestry.com. Carmine died in 1930 after the US Census was taken while Brigida died in 1937 (3 years before the 1940 Census). They apparently did not have social security cards, nor do they appear to have applied to become naturalized US Citizens. I learned a lot by reading this.
I recall my mother saying that her mom stated that they didn't like talking about the fact that her mom, Brigida, was remarried. It is unclear how soon after Carmine died it had been when Brigida remarried. I personally think it might have been pretty soon after Carmine's death as my grandmother and her sister were upset with their mother.
I was able to obtain Carmine's official death certificate however I was not able to obtain a copy of Brigida's death certificate. What made things a bit difficult was that Brigida was buried with Carmine under his surname (Giannetta.)
My cousin had learned of the surname of the man Brigida married after Carmine however as she was buried as Giannetta I assumed she did not take the last name of her second (2nd) husband so the death record (exact date, etc...) had become a dead end... until last week.
I came across an Italian Genealogy Site "The Italian Genealogical Group" an organization dedicated to furthering Italian family history and genealogy and primarily those whose families immigrated to New York (like mine had.)
I decided to use their online vital records search on death records. Once again I found Carmine and once again I did not find Brigida. Then, somewhat on a whim, searched for her using the surname of her second husband along with the first initial of her first name "B".
A matched record with her first name was spelled as "Bricita", which was a phonetic spelling of her name which my mother and her mother used whenever they wrote Brigida's name. She had indeed taken her 2nd husband's last name when she remarried, and I can imagine that this might have been another reason why my Grandmother and her sister did not like the fact she had remarried.
My recommendation would be to include less likely search information when you hit a dead end and you may just find the information you are looking for.