I literally burst out laughing to that :) - How are you so good at each language?
I didn't try it but in English, "we are a multicultural family" would be a better translation.
Does "internazionale" have the meaning of "from another country" or of "of people from different countries"?
It means "composed by people from different countries". To say "from another country" we use "straniero" that has the same meaning of "foreign".
i believe the " We are one international family" should be also accepted as i think "una" can be number too, am i right?