People’s average age is about 44 in Italy, while a generation in the second half of the 20th century lasted about 29 years there.
So for two generations:
44+2*29=102
So the grandma of the average Italian would have been 17 years old in 1940 and thus was not born in 1918, but in 1923.
No “gugu gaga”, but still quite young.
On average.




















My grandmas were bom in 1914 and 1908.
So together with your value, 1923 sounds somewhat realistic.
I am not Italian, tlough. :-)