I really don't understand how having two miscarriages, being an only child and having parents who divorced when she was young are mitigating factors by any stretch of the imagination. I know that miscarriages are heartbreaking, and I am not trying to downplay that at all, but she was only 27 years old and had at least another decade to try to conceive. (And again, what does being an old child of divorced parents have to do with anything?!)
Maybe the article just failed to mention this, but I would think there should also be an attempted murder charge for what she did to the poor mother. And I thought there was a murder charge between 1st degree (premeditated) and manslaughter where you act recklessly enough to do something where there is a reasonable likelihood someone will die? I would think that would be applicable and carry a heavier sentence than manslaughter. But then again, I don't know much about Hong Kong's judicial system; just figured this would have survived from British common law.
The whole thing is incredibly tragic.
I'm glad they survived though!