Born to the Titans Cronus and Rhea, Demeter is a 1st generation Olympian. Demeter is like Themis in several ways.

1.) She is the Goddess of Sacred Law.

Themis is the Goddess of Law and Order.

2.) Demeter is responsible for the food we consume and she presides over the cycle of life and death with food and nature. Themis gave birth to personifications of life (The Horae) and death (The Moirai).

3.) Themis said they have an affinity 

Demeter is closest to her daughter Persephone (father Zeus). When Hades kidnaped the girl and took her for his wife, Demeter stopped all the food from growing and no one could eat. Starving, the people went to Zeus, who told his brother Hades, that he’d have to share Persephone with her mother. So, four months out of the year mother and daughter are reunited resulting in the abundant days of Summer. When Persephone goes back to Hades, Demeter gets depressed and causes “the little death,” or Fall and then Winter. Demeter has also had a child with Poseidon