Here's what I will say. I acknowledge the murkiness of euthanasia, in most cases. There is rarely a perfect scenario where one clear decision is made with ease, it appears even the laws are murky. Life presents painful, confusing scenarios and I don't know if there is always a right or even best way to handle them.
I do think a parent is most often the best person to decide something like this for minors, and again, murkiness exists. What if they've abused the child before, what if they have a criminal history, or a mental illness, what if, what if? In the case I have presented, the woman is a criminal and a drug addict. What bearing does that have?
I don't think a parent should be able to pull a Robert Latimer. I do think medical and mental health professionals should be involved in any decision to end a life in this way. Again, what if the professional is wrong?
The core of the issue appears to be one of opinion and likely spiritual opinion. I am not of the belief life is, by default, better than death, and that shapes my opinions. I don't follow a god figure, and that shapes my opinions.
I cannot say what is right or wrong, and I won't attempt to draw too many lines.