She makes you look crazy. If you try to confront her about something she's done, she'll tell you that you have "a very vivid imagination" (this is a phrase commonly used by abusers of all sorts to invalidate your experience of their abuse) that you don't know what you're talking about, or that she has no idea what you're talking about. She will claim not to remember even very memorable events, flatly denying they ever happened, nor will she ever acknowledge any possibility that she might have forgotten. This is an extremely aggressive and exceptionally infuriating tactic called "gaslighting," common to abusers of all kinds. Your perceptions of reality are continually undermined so that you end up without any confidence in your intuition, your memory or your powers of reasoning. This makes you a much better victim for the abuser.
Narcissists gaslight routinely. The narcissist will either insinuate or will tell you outright that you're unstable, otherwise you wouldn't believe such ridiculous things or be so uncooperative. You're oversensitive. You're imagining things. You're hysterical. You're completely unreasonable. You're over-reacting, like you always do. She'll talk to you when you've calmed down and aren't so irrational. She may even characterize you as being neurotic or psychotic.
Once she's constructed these fantasies of your emotional pathologies, she'll tell others about them, as always, presenting her smears as expressions of concern and declaring her own helpless victimhood. She didn't do anything. She has no idea why you're so irrationally angry with her. You've hurt her terribly. She thinks you may need psychotherapy. She loves you very much and would do anything to make you happy, but she just doesn't know what to do. You keep pushing her away when all she wants to do is help you.
She has simultaneously absolved herself of any responsibility for your obvious antipathy towards her, implied that it's something fundamentally wrong with you that makes you angry with her, and undermined your credibility with her listeners. She plays the role of the doting mother so perfectly that no one will believe you.