This elevates the older child's position in the family. Tell big sister that you need her help and show her what to do. Helping one another can bring out the best in the helper and the one being helped. Doing good for each other promotes good relationships between siblings. This builds social skills so that your children grow up knowing how to give and receive.
Older siblings shine when they pass a skill on to a younger one.
Encourage your child to take on the role of teacher. When our Matthew took on the role of baseball coach to his younger brother, Stephen, they spent more time together and grew closer. Encourage siblings to comfort one another. Friends come and go, but siblings are forever. Our first two children, Jimmy and Bobby, squabbled a lot, especially in their early years, yet they eventually grew closer and closer.