I think if you're a good listener some people can latch on and take advantage of that, it sounds like she's taken far more than she's given and you're now evaluating this friendship. Sometimes asserting boundaries can help I think but other times it won't help. I think if she's truly narcissistic and doesn't want to address that then it's not likely to help.

I would say you deserve better and a more reciprocal friendship.

Hugs!