Board Thread:Legitimate Canon Questions/@comment-82.132.230.65-20170826182703/@comment-4091815-20170826192313

Second question first - There is no canonical answer.

She never says "I knew all this because ..." We are led to believe that she learned the information in the several years between the Nemeton saving her and the creation of her plan to use the Nemeton in a similar fashion to kill the Alpha Pack.