In Snorri's "Prose Edda" he list twelve attendants to Frigg/a who live with her in her hall, Fensalir.
Frigga is called first among the asynjur (the goddesses). She is the All-Mother (to contrast with Odin's All-Father) overseeing her attendant goddesses. These twelve lesser goddesses who attend her at Fensalir are seen by some as aspects of Frigga, so not individual beings, who represent the moons.
They can in fact be viewed either as separate figures or as hypostases, or aspects of the goddess Herself– personae which she adopts in order to play a more active role. As a polytheist, I see all the twelve goddesses as separate individuals, with their own personalities, roles and life cycles.
In the list of goddesses Fulla is described as the fifth, although one of the most important and having the closest relationship with Frigga, hence the word Sister, which Alice Karlsdottir names her in her "Magic of the Norse Goddesses". Her name means "full" - usually taken to mean fullness or abundance.
Fulla is seen in several myths as one of the goddesses seated as judges in the high seats in the great halls of Asgard. Fulla often appears as a goddess of rank and stature and is names among the lawgivers in the 'Skaldskaparmal'. She seems to be a favoured and constant companion of Frigg. In the "Second Meresburn Charm", Fulla (Volla) is called the Sister of Frigg.
Jakob Grimm suggests that Fulla might have been linked to the full moon, because her name is similar to the Gothic word 'fullips' and the Lithuanian Pilnatis - and because Frigg is often connected with the constellation of Orion. This is interesting as in the heathen tradition the moon is often seen as a male deity.
Fulla is described as a beautiful maiden wearing her long golden hair loose, restrained only by a golden band, circlet or snood. The unbound hair will probably be a sign that Fulla is unmarried in old Norse society and the golden circlet a sign of nobility. Karlsdottir likens her long flowing hair to that of Sif and says the band could link her to the binding of the harvested sheaf, so it is possible Fulla represents the fullness and bounty of the earth.
Grimm compares her to the German fertility figure, Dame Habonde or Abundia.
Fulla's primary role seems to be as Frigg's main companion, confidante and advisor. Fulla has custody of the Queen of the Aesir's ashen casket, which mythologically (according to Karlsdottir again) could symbolise the container of "the divine mother's blessings, prosperity and fertility" and Fulla would be the one in charge of preserving this power until Frigg is ready to dispense it.
In the Grimnismal in the Elder Edda, Fulla is used by Frigg to pass on some misinformation in order to confuse the king, Geirrod, as Odin had been taunting Frigg over Geirrod, thus leading him to have favours revoked by Odin. In Saxo's "Gesta Danorum", Fulla enlists the aid of a dwarf to help Frigg prevent Odin from finding out that Frigg had stolen a piece of gold from one of his statues to make a necklace. A true friend and confidance indeed!
It is also written that Fulla has charge of Frigg's shoes. In those days, shoes were a symbol of wealth and prestige. The foot also has connotation of fertility - both in Germanic and Celtic folklore the foot was often used to indicate the penis. The Jera rune (rune of harvest) is linked to her.
In the 'Gisla saga Surssonar' the hero states just before his death:
"My Fulla, fair-faced, the goddess of stories, who gladdens me much, shall hear of her friend
standing straight, unafraid in the rain or the spears."
When we do a sumbel (small ritual involving toasting and drinking) to Fulla we would prepare the harrow (altar) with things to do with abundance and fertility, such as sheafs of corn, some gold or golden objects, a casket and a small shoe. We then toast her and call to her.
CALL TO FULLA
Fulla, Volla, Fylla, Abundia -
Sister of Frigg, Maid of Honour, Hail!
Lady of the chamber,
Mistress of wealth,
Guardian of treasures -
Bring us abundance.
Weaver of the ribbon,
Lady of the ash,
Keeper of the casket,
Adorn our lives.
Keeper of jewels,
Keeper of shoes
Keeper of secrets,
Ward well our dreams.
Come with gift and greeting
Come with fun and folly
Come with lore and laughter -
Sweet sister of the gods - come!