The 1940 census lists Matilda Fittin, Daniel Fittin, and daughter Matilda Fittin, born in 1916. There is a tree in Ancestry that lists her maiden name as Macre.
You can send away for her death certificate. Search NJ vital records and look for the Genealogical Request. There is a fee for the search. It's $25 plus $1 for every additional year.
If you Google (search) Matilda Fittin there is an recent obituary for her son Paul T. Fittin.