Complex sentence: She is mentioned in the "Ynglinga saga" and a late medieval Icelandic tale, and in the latter source she is Odin's mistress and the mother of the semi-goddesses Torgerd and Irpa.
Split into simpler sentences: She is mentioned in the "Ynglinga saga" and a late medieval Icelandic tale. In the latter source she is Odin's mistress and the mother of the demi-goddesses Þorgerðr and Irpa.