Chapter 2 treats the family as a school where love is learned directionally: upward toward parents and grandparents, horizontally toward spouse and siblings, and downward toward children. Happiness depends on these forms of love being present and integrated rather than isolated.
The chapter especially insists that three generations belong together. Grandparents, parents, and children are not sentimental extras but the structure through which people learn to honor the past, inhabit the present, and invest in the future.
It also treats siblings and grandparents as formative, not peripheral. Siblings train peer love, and grandparents embody both living history and a family-scale image of God.