She knew what she was doing, and probably has been doing it all her life. She was not trained by Trump to be that way, she is just looking to pawn of her own accountability for her actions on him. What he did for them is show them that being loud and proud about their hatred was fine, that is all.
What she is upset about is finding out that they were never important to him either. That is all this is. The greatest supportors can end up being the worst enemies, when they feel betrayed by the person they believed in. She is not mature though, because she is not accepting that what she did is just who she is.