A family provides the safety net for their children, so they can be fed,
clothed, sheltered, educated, and loved. It doesn't matter what the
make-up is of the family, it matters if they are supported in their
efforts to protect and nourish their children.
Without a family, children can be hungry, malnourished, homeless, illiterate, and unloved.
The family is a natural and essential part of the foundations of a healthy society.
In fact there are two important family structures:
The nuclear family (mother, father, children)
The extended family (nuclear family + aunts, uncles, grand parents, etc.)
Of course this only applies where the family itself is healthy, but the
fact that SOME families are abusive or ineffectual in some way does NOT
detract from the importance of the family as such.