Just draw one set of grandparents, artists choice. Include Mom, Dad, 16 to 19 year old sister, 11 to 13 year old brother and baby. Your rotating view should have a profile, a 3/4view, a frontal , a 3/4 view and profile view in the opposite direction. What is important here is that your various heads all look consistent and from the same family. The heads should resemble each other.