Norns

The Norns were goddesses of destiny or fate. They were responsible for guarding the Well of Urda (Urdarbrunnr), one of the three wells under the Yggdrasil (World Tree). Snorri Sturluson, who wrote in the Prose Edda, said that it was also called "Weird's well". The well was holy, and the Aesir often gathered there to hold court.

Like their Greek and Roman counterparts, there were three goddesses associated with fate. These three goddesses were named Urda ("past", also Urd, Weird or Wyrd), Verdani ("present"), and Skuld ("future"). The norns were descended from the Aesir. In the Voluspa, they were not given their names, but the poem did call them "Fated", "Becoming" and "Must-be".

The Norns were depicted in three stages of womanhood. Verdani as a young maiden, Skuld as mature woman or a mother, and Urda as an old hag. However, the Voluspa (20) say they were 3 girls or maidens, thus they appeared to be younger. They were also often depicted carrying a long rope or the thread of life in their hands.

In the Voluspa, Skuld was also a Valkyrie in the company of other Valkyries. It doesn't say anything about Skuld being a norn in this poem.

She saw valkyries coming from far and wide,
ready to ride to the Gothic nation;
Skuld held one shield, Skogul another,
Gunn, Hild, Gondul, and Spear-Skogul;
now the ladies of the General, the valkyries are counted up,
ready to ride the earth.

Voluspa 30

The Gylfaginning (Prose Edda), clearly indicated Skuld is both Norn and Valkyrie; that she was the youngest norn.

These are called valkyries. Odin sends them to every battle. They allot death to men and govern victory. Gunn and Rota and the youngest norn, called Skuld, always ride to choose who shall be slain and to govern the killings.

Gylfaginning 35 (Prose Edda)

However, these three norns were not the only norns to exist. Snorri reported others being present when people are born, shaping their lives. Some of these norns were of the race of elves, while others were that of the dwarves. Snorri also wrote that the "good norns" of noble birth were responsible for shaping good or successful lives, while evil norns were responsible for misfortune.