Given the ways that English works, one of which is the removal of all sorts of deliberate and tedious indications as to what one is talking about usually found in the Germanic languages, when one writes in English and uses the phrase 'other languages' but there is no specific language under discussion it should be understood that other languages refers to languages other than English.
The parent is making the point that the language the grandparent is referring to is irrelevant to the language of an arbitrary individual included in the word "we".
It was just rhetorical. As the sibling comment alluded to, it can come off as quite anglocentric. There is some historical relevance to this point - much of the technology we use today was created with such biases baked in. I apologize if this came off as snarky.
