I think that womanhood can only be measured by the one who is living it. Personally, I love being a wife, mother, and friend. However, it is not for everyone. I have friends who have lived single lives contently. Just because they don't want to be wives or mothers doesn't make them less "woman."
With that being said, I do believe that each woman (or man for that matter) should live responsibly. Dashingscorpio said it best with "Be honest, responsible, and accountable for choices they make in life."