Complex sentence: As a young girl she witnessed the Jinshin War and later, according to the Man'yōshū (The Anthology of Ten Thousand Leaves), became the first Saiō to serve at Ise Shrine.
Split into simpler sentences: As a young girl she witnessed the Jinshin War. According to the Man'yōshū (The Anthology of Ten Thousand Leaves), she became the first Saiō to serve at Ise Shrine.