Everyone has narcissistic tendencies. If we don't, we lose ourselves to others and there can be no such thing as a boundary. Vaknin has a lot of good stuff on his site. I would venture to say that everything he lists is within all of us, to one degree or another. Who hasn't succumbed to "narcissistic supply?" Giving advice on this board fulfills that very function. Only when things become excessive are they a problem.
I'm not saying you, your mother or anyone else is narcissistic. Finding a true narcissist is rare, IMO. But the elements Vaknin describes in his many aspects of narcissism can be very useful information, IMO.