Snorri Thorfinnsson in "Eirik the Red’s Saga"
Chapter 12
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[...] Karlsefni’s son was born there [in Vinland] the first autumn and was three years old when they left.
Chapter 14
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Karlsefni’s son Snorri had a daughter, Hallfrid, who was the mother of Bishop Thorlak Runolfsson. [...]
Thorgeir, Snorri’s son, was the father of Yngvild, the mother of Bishop Brand.
Source: Keneva Kunz, trans., "[Snorri Thorfinnsson in] Eirik the Red's Saga" in The Sagas of Icelanders: A Selection, preface by Jane Smiley, introduction by Robert Kellogg, (New York, London, Victoria (Australia), Toronto, Auckland: The Penguin Group, 2000), 653-674. Notes: Translations first published in "The Complete Sagas of Icelanders," volumes I-V (forty-nine tales), Leifur Eiriksson Publishing, Ltd., Iceland, 1997.