^ TBH it seems like your rather trying to demonize the mother
It seems to me she got high as fuck and wanted to put on a movie for her kid so he at least wouldn't be wandering around the house or something. Obviously that is still VERY irresponsible, but it's not like she just had absolutely NO regard for her child's safety.
She was probably just too fucked up while trying to put on The Wiggles, knocked over the TV and the child just happened to be sitting there.... the same thing could have happened if she was sober.
I was going to respond, but several people who posted above did most of it for me

Maybe my perspective on this is different than yours - I am a parent.
I enjoy drugs very much, but I have never been responsible for my kids (or any others) while totally fucked out of my mind.
I have smoked weed or drunk a glass of wine while playing with my kids, and even taken san pedro cactus and ayahuasca while they were in the same house, but their mother was responsible for them (and completely sober) at the time.
I cannot understand how someone could get royally fucked while having full responsibility for their kids (unless maybe their kids are 17 at the time

). When I had a 4-month old infant, I felt incredibly high just to have such a beautiful being in my family. The intensity of the birth was fading slightly, but I did not need to take drugs to feel amazing.
If someone else wants to take heroin with a 4-month old in the house, I think it is a shame, but also that it is their right to do so (or should be, anyway). But if they get so fucked up that they might knock over a heavy TV without knowing it, that is too fucked up to take care of a baby. Knocking the TV over on the baby was really bad luck, but the fact that she got so fucked up despite having the responsibility is the real problem, in my mind. I would punish all parents who disregard their responsibility for their children in such a way, if I could, but we don't know about most of them. In this case, because of bad luck, we found out about it. I don't think that she should be charged with murder - or possession/use of drugs, which shouldn't be crimes at all in my mind - but she definitely needs to re-think her priorities, which clearly involve drugs taking precedence over parenting.