Narcissistic Mothers' vanity is a classic one of their traits. Having said that, not all of them have it, so if your mother isn't vain, it doesn't mean she's not narcissistic. (Nor does a good interest in one's appearance, by itself, mean narcissism.)
Now, we all like to look well. I'm not talking about normal self-care or pride in your appearance.
I'm talking about an obsession with her looks. I'm talking about ALWAYS being perfectly dressed and made-up - perhaps even just to take out the rubbish bins! I'm talking about over-dressing, i.e. wearing too formal an outfit, and too much jewellery and make-up for an occasion. (Again, people sometimes do this because they misjudge it. And some people just like jewellery and make-up more than others. But this vanity is more than that.)
It might also involve excessive preening of herself in the mirror. Admiring herself, appreciating herself and her beauty.
Narcissistic Mothers' vanity can include body size, you won't be surprised to read. They often hate being fat, or perhaps even normal-sized, and are very judgemental of people who are overweight. And they can thus put huge pressure onto their daughters to be equally slender, which can often lead to eating disorders.
If she is an Engulfing Mother she might project her vanity onto her daughter. She might insist that her daughter remains very thin, for example. For Narcissistic Mothers who have this extreme vanity, ageing is even more difficult than for the rest of us. The rest of us mourn whatever beauty youth gave us - but for Narcissistic Mothers ageing is an absolute disaster. You may find therefore that they become addicted to cosmetic surgery, or maybe just to dressing much younger than they are, so they can hang onto their youth with every fibre of their being.
There is an irony to all this of course. Many Daughters of Narcissistic Mothers have real trouble with self-care. They were taught, growing up, that they weren't worth looking after, and that's the message they internalised.
Or, another form of vanity for narcissists is about their intelligence, real or imagined. Such narcissists might not be too worried about their looks or appearance. They get their strokes from being so clever - again, real or imagined intelligence. They don't necessarily have to actually be that clever to feel that they're clever. My own mother is like that. All my life I heard how intelligent she was, but looking back, there wasn't really a whole lot of evidence of it.
Download "You're Not Crazy - It's Your Mother" as an audio book. Professionally recorded by me, Danu, in my warm Irish accent, this is another way to access the information you deserve and need.