Elessari was a human female, and a member the Council of Elders. She had long gray hair and carried a dagger. She supported controlling Nasuada as she led the Varden. The other four on the council are: Jörmundur, Falberd, Sabrae, and Umérth.
Paolini perhaps created the name out of inspiration by the Lord of the Rings. The name Elessari sounds very similar to Elessar which was the elven name for Aragorn son of Arathorn in Tolkien's mythology.