They don't care though children are crying in train.
They don't mind children are crying in the subway.

日本だと子供連れで電車乗るのすげー気を使うけど、アメリカだとみんな子供におおらかで優しいから、泣こうがわめこうが気にしなくて良くてそこは気が楽だよねー。