Princess Saho is the personification of Mount Saho, which is located to the east of Nara. As the eastern direction is associated with the season spring, Princess Saho is considered the goddess of spring, and her name is one of the season words for spring in certain forms of Japanese poetry such as renga, haikai, and haiku.
Princess Tatsuta is frequently regarded to be the goddess of sewing and dyeing, and the same association is applied to Princess Saho. One common trope in Japanese classical poetry is that the colorful autumn leaves of Mount Tatsuta are dyed by Princess Tatsuta, and the spring mist like a thin veil draping over Mount Saho is weaved by Princess Saho.
Princess Saho can also be read about here.