I can totally see why everybody would be mad at her for keeping that big secret about knowing but I kinda see where she was coming from. The kennishes would have definitely taken daphne away, and she knew Bay was in a place where she was being well taken care of. I'd even go so far as to say I would have done the same thing in her position but I'm a strong believer in nurture over nature and I agree with what she was telling daphne that the strongest familial bonds are the ones we make through knowing and loving each other more so than by blood.
I'm not saying that what she did is easily forgivable. I'm saying that there is two sides to this story and her case is a good one.