Sorry. Had a massive flashback.
I was always a loner, even as a child, barely dated, had exactly two boyfriends (dated the first one at 28) and married DH at 35.
I could not stand the implications that were tossed around as to why I had no constant male companion, and the reasons why ("I don't understand it.......Brandydan's not ugly/mean/dumb/a junkie..why doesn't she have a man?", or the whispered wonderings of which gender I preferred).
I was perfectly happy with my own company. I had a decent nest egg, a nice apartment in a nice building, my own car, education that I paid for, a cat that was always happy to be pampered, a slew of nieces and nephews that I adored and spent a lot of time with, siblings that always loved me, etc.......yet somehow, there was something 'wrong' with me.
When I met DH, it was as friends, and we both never expected it to go further than that. Had the 'spark' never been ignited, I think - No, I KNOW - that I would still be comfortable being single.
Being alone is different than being lonely, and I think that the OP's lady-in-question is not cranky because she does not have a man, but cranky because others overlook her and see only a single person and for them somehow that is not normal.