It took me a very long time to see a pattern of convert narcissism and toxicity in one of my friends.

Had I caught this soon enough, I would not be in a predictament that I am in now. Because I used to be very close to her and then started distancing myself as I saw her true color, she is now questioning me why.

I don't know how to respond, as I know that her response to whatever I say would not be sincere.

A while ago, I set a boundary with her a little more explicitly when I saw that she continues to push boundaries when I try to set them gently and implicitly.

She acted as if she understood by saying all the right words (she tends to exaggerates in a way that is too saintly/ angelic to be true). Then she followed these words with passive-aggressive behavior that clearly showed she was offended. I have also seen her do the same to someone else.

How do I set a firm boundary with her, when I know that she will only pretend to understand?