There's a book with Ruth Rendell with the same title, which is a direct quote from a poem by George Herbert (nope, I've never heard of him either ...) https://www.poetryfoundation.org/poems/44364/jordan-i
I take it to mean that the woman in question was special to very few people during her life and it's something I share. I always felt second-class compared to others, having very little self-esteem whilst growing up. People, especially men, were wont to use me, but oft professed a deep love for somebody else. That last sentence sounds very Victorian in meaning, but hey, why not?
I fall deeply in love all too easily and being autistic, I cannot hide my feelings. With the exception of the man I'm married to, no other man has given a flying fig about my limited amount of self-confidence, choosing to bang on about another bloody woman (or women ...) What I really like, and I'll emphasise that point, is hearing all about just how deep the strength of their feelings go towards someone else. Oh, it's really nice to witness such devotion, especially when it's aimed at another person. Oh joy.
