considering she has such a bad reaction towards Kyoko and there's never been any mention of Kyoko's father...I'm pretty sure the story ends in much more than just betrayal.
It's not really much more than that, here's a link to the next chapter: https://www.facebook.com/groups/2211763929/permalink/10153719739943930/
And I don't think this justifies the mother's behaviour towards Kyoko, the child had no fault. I know she must have been a constant reminder, but still.
Well so long as it wasn't rape I am good. I don't like the mother's treatment, but I hope the reason isn't something like that.
I am just glad that it seems to be a story of betrayal instead of something horrible.