Complex sentence: There, he became acquainted with Þorsteinn's daughter Helga the fair, who was reputedly the most beautiful woman in Iceland and her hair was so ample that she could hide herself in it.
Split into simpler sentences: There, he became acquainted with "Þorsteinn's" daughter, Helga the fair, reputedly the most beautiful woman in Iceland. Her hair was so ample that she could hide herself in it.