Angelina is widowed by 1940, but couldn't find a death for Angelo.
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K4FH-W2H : 17 May 2014), Angelina Gallo, Ashland Town, Middlesex, Massachusetts, United States; citing enumeration district (ED) 9-41, sheet 64A, family 11, NARA digital publication T627 (Washington, D.C.: National Archives and Records Administration, 2012), roll 1602.
Ashland Town, Middlesex, Massachusetts
Angelina Gallo Head F 52 Italy Widowed
Mary Gallo Dau F 18 Massachusetts
Rose Gallo Dau F 16 Massachusetts
Rocco Gallo Son M 14 Massachusetts
Jennie Gallo Daur F 12 Massachusetts
Don't know if the record below is at all related: ie. Angela vs Angelina
"United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:VM66-D3L : 19 May 2014), Angela Gallo, 15 Apr 1966; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).
Given Name ? Angela
Birth Date 15 Apr 1889 Age 77
Last Place of Residence Ashland, Middlesex, Massachusetts
Previous Residence Postal Code 01721
Event Date 15 Apr 1966