Everything which is really meaninful in the family, the mother's affection for his son, the son's respect for his father, the love among brethren, or the spouse's devotion are all values which are not ultimately defensible by compulsory law.
A man can be physically compelled to feed his son but not to love him, to avoid visiting a mistress but not to violate the eight commandment.
The family is based on values, thus can not be defended trough coercion but only through education on values, an education which itself can not be coercively imposed but only voluntarily accepted.
The article 51 of the Constitution of the Republic of Costa Rica accurately (though needlessly) states that the family is a natural element of the society as well as its foundation, however aspires to an utopia when it declares the State as its protector.
To be sure, the one thing the government can do for advancing the wealfare of the institution of the family is to laisser-faire-et-laisser-passer. Everything else is counterproductive.
Family is not a legal category. Therefore it can not be defended through coercion, this is: by government.