Commonly Used Terms
Parents (Married/Unmarried); Spouses; Step-Parents; Children under age 21 (full/half/step); Children under age 21 (full/half/step)away at school AND claimed as a tax dependant; Unborn children of any family member.
Who Doesn't Count:
Caretaker relatives (Grandparents, Uncles, etc.); Legal guardians; Foster parents; Recipients of most forms of public assistance; Unmarried father of an unborn child if he has no other children with the pregnant woman; Roomates, friends, and others.