I have no experience with children, but wanted to highlight my experience growing in a multi-lingual area.

My family was based in central India. My mom spoke Telugu, and were taught/forced to speak only in English at school. My mom encouraged speaking English at home - her reasons as that it was harder for us to pick up English than to speak our native language Telugu, or the language of our city - Urdu/Hindi/A mix of English, Hindi, Urdu, Telugu. We were encouraged to read books in Telugu, took after school certifications in Hindi, and attended Telugu mass as often as the English ones at church. I am fluent in 3 languages. English, Telugu and Hindi - written and verbal. I can understand Urdu quite easily, can’t read though.

We had neighbours who spoke Hindi/Urdu exclusively. Church groups spoke Tamil/Malayalam. I can understand Tamil quite easily, but can barely understand Malayalam or kannada (all these being our neighbouring states, and our family friends belonged to communities that spoke this).

When I migrated to Toronto, one of my first jobs was as a baby sitter to a 4 MO. The only requirement was that I spoke Telugu around the child, since one of the parent’s was an American citizen and they didn’t speak Telugu at home.