Helga, wife of Thors Snorresson and mother to Thorfinn and Ylva, is the daughter of Sigvaldi, former chief of the Jomsvikings, and niece of Thorkell the Tall, placing her within the Jomsviking nobility. Her marriage to Thors, then a Jomsviking captain, was arranged by her father. Their first child, Ylva, was born while Thors remained active with the Jomsvikings. Following Thors' change of heart during the Battle of Hjörungavágr in 986 and his desertion, Helga fled Jomsborg with him and infant Ylva after Thors defeated Thorkell, who tried to stop them. They settled in remote Iceland to escape warfare.

There, Helga established a home. Described as warm and kind-hearted with blonde hair, blue eyes, pale skin, and a slender build, she typically wore a white bandana, short red cape, and white and light green attire. She nurtured a peaceful environment. After Thors' death in 1002 during a journey to England, Helga remained in Iceland with Ylva, learning of Thors' fate and Thorfinn's disappearance from Leif Erikson in 1003. Throughout Thorfinn's long absence, she maintained the household alongside Ylva, demonstrating quiet resilience.

Helga reappeared in late 1018 when Thorfinn returned to Iceland after gaining his freedom, reuniting with him at their farm with relief. She continued providing familial support as Thorfinn planned his Vinland expedition. Historical records note Thorfinn Karlsefni's mother was named Thorunn, differing from her portrayal in the series adaptation. Her character consistently emphasizes compassion and stability, serving as an emotional anchor through loss and reunion. She does not physically appear beyond this point but remains referenced in relation to Thorfinn's motivations and backstory.