It would be a terrific shame for these children not to be bilingual. My DH’s sister met and married an Italian and moved there in 1968. When he died 3 years ago he could scarcely utter a word of English. Their children, now in their late 40’s only speak Italian, never being spoken to in English. Poor sister never worked, her only role was to provide 3 meals family meals a day and she has quite poor English herself now.
Girls grammars in the 60s (and beyond)

