A truly annoying situation. 'Family' is a singular, collective noun. However, when talking about a family, the correct pronoun is 'they'. If you use the word family, the word follows the rules of 'it'. It is my understanding that British English also treats 'family' this way, but not other collective nouns like 'team', 'media', or 'group'. I could be wrong about that, though. In American English, most of the time, all collective nouns are treated as singular for conjugation. Even in American English, these rules are argued, though. Some news outlets write "media has" while others write "media have". Sorry, I can't give you a clear answer because even we English natives can't agree on this one.

Like Johnny said. As far as British vs. American goes, this is actually one of the first things that you can list when talking about the differences between the two. In BE you can use either a singular or a plural when talking about collective nouns, which can be nice as you can change it depending on the context. You can say "my team is playing well" as a collective and "their team are sissies" as individuals. In AE you'd have to say "their team is a bunch of sissies". Pardon the colorful example :)

singular = Family plural = Families

I saw the same question few weeks ago on this site. There was no a clear answer. People said it depends on what you meant.