Complex sentence: Miriel Serinde, mother of Feanor, also has silver hair (as did Earwen, daughter of Olwe, mother of Galadriel) and is possibly related to the Sindar, as she is only Noldor by marriage, as far as is known.
Split into simpler sentences: Miriel Serinde, mother of Feanor, also has silver hair, as did Earwen, daughter of Olwe, mother of Galadriel. Miriel, by this measure, is possibly related to the Sindar, as she is, like Earwen, only Noldor by marriage, as far as is known.