Is the final Broodmother in DAO: Awakening Morrigan?

In Dragon Age Origins Morrigan escapes pregnant with the Grey Warden baby. In the "Witch Hunt" quest line she goes through the type of mirror that turns Tamlen into a shriek. In the "Awakening" quest line, the final boss is a brood mother that has a very similar appearance to Morrigan. Since women with taint turn into brood mothers and the mirrors have the ability to taint, is it just a coincidence or is it actually her?