Judging by one of the earlier cover pics, Nukumi's body was more like Asuna's when she was still a JK. Before she chonked up a tad below the boobs.
In other words, short of bizarre author contrivance, there is no way that Nukumi (like the rest of them, presumably) wasn't fighting the guys off on a daily basis from about age 12 until the point she shut herself away in a room and started hiding from the world. So if she is still alone at that point, she only has personal choice to blame for it.
I'd certainly go for someone like that... though at my current stage I'm just sick and tired of all my relationships going wrong when all I wanted from the very first was stability...