I read an interview once with an American woman who moved to Italy with her Italian husband. They lived in the same apartment building as her in-laws and in the morning her son would walk down to Nonna's for breakfast.

I love the idea of family living within walking distance but in their own domiciles, like townhomes or apartments or condos in the same building. This is another great argument for mixed zoning. A 55+ condo building in the same neighborhood with single family homes for large families and smaller townhomes/apartments for families that are just getting started.