... I'm usually not a fan of Yukkuri abuse... but this one really deserved it. It embodies all the worst traits of Yukkuri, and more -- even the most selfish and cruel yukkuri will usually care about their own offspring, but this one callously sacrificed and abused them when it served her needs. And unlike most yukkuri, she was definitely smart enough to know what she was doing.
The sequel story makes it even worse. Although her punishment gets truly excessive, when Youmu finally rescues her from it and nurses her back to health, although she fakes gratitude she still plans to kill Youmu and conquer the world.
She's the worst Yukkuri in the world.
Poor Youmu... she believed in the best aspects of Yukkuri... but ended up backing one that embodied the worst.
Now wait... I think this one was taking care of its offspring by having them spirited away by Marisas.. it was others' offspring it was sacrificing. (Unless you mean the part where it eats its baby, but that was a combination of stupidity and Yuyuko hitting it.)
As I remember the story... she was having most of them spirited away... but would leave a few of hers behind to avoid raising suspicion. She didn't even treat those like her children, refusing to take care of them and calling them food. I might want to reread to be sure.
^ Yes, it's like that. The "food" KoReimu knew they were the sisters of the other Yukkuri, in post #653. The only other Yukkuri was the captured and silenced Reimu.