Moon Girl by Beatrix Tambunan
Illustrated colorful children's book telling a story of two sisters.
One is sun girl who keeps the sun out during the day hours so everybody can go to work, plants can grow, etc.
Moon girl takes over when the sun goes down so creatures can use the moon rays to travel and crawl outside.
Moon girl was feeling sad and not loved so she traveled to Jupiter and realized there was nothing growing there at all.
She came back to Earth and everybody was happy to see her because she does have an important job.