Sigyn is a Norse Goddess.
Sigyn was known for being the loving, faithful second wife of the wily trickster God Loki after he was married to Angrboða. With Loki, Sigyn had two sons whose names were Vali and the other son was variously rendered as either Narfi or Nari.
Due to the fragmentary nature of the primary sources for Norse mythology, only one scrap of lore regarding Sigyn survives that gives any indication of her personality and mythological roles: the tale of Loki’s punishment for killing Baldur. In that tale, when the Gods captured Loki, they turned one of his sons, Vali (not to be confused with the Vali who avenged Baldur’s death), into a wolf. The wolf then ripped apart Narfi/Nari. The boy’s entrails hardened into an iron chain, and the Gods used this grotesque fetter to bind Loki in a cave deep beneath the earth. The Gods also placed a snake above Loki that would drip venom onto his head.
Like a model of a traditional, dutiful wife, Sigyn sat by Loki’s side with a bowl to catch the drops of the snake venom so that they wouldn’t touch her husband’s head. Every so often, however, she would have to leave the cave to pour out the bowl. In her absence, a few drops of poisonous venom would fall onto Loki’s forehead. This caused him to writhe in agony, which in turn caused earthquakes on the earth’s surface of Midgard, the world of humanity.
Sigyn’s story is also one of victory: victory over wrenching circumstances, over pain, loss, despair, and anguish. She chooses to endure and by doing so, she triumphs. As Fuensanta Arismendi, an ardent Sigyn’s woman once said: Sigyn’s strength is in her heart. Her heart is invincible.
Taken from lore, It seems that Sigyn’s world was defined by love: love of her husband, love of her children, love of her family as a whole. She consciously chose to honour the commitments of her heart and to endure in the face of unprecedented loss, grief, and misery. Loki’s ordeal in the cave, perhaps the defining moment of his Mytho's, was also her ordeal in the cave. The difference is that she consciously chose to endure it.
Sigyn was known to be a loyal, devoted wife to Loki. She, however, isn’t depicted as bold, brash, or sexually independent (like Freyja).