Yes that's what I meant. I wonder if her mother drank a lot whilst pregnant or like a girl I knew caught meningitis when very young, which resulted in a severe learning delay, or did she have an accident resulting in a brain injury....
I wondered if certain parts of the brain like empathy, reasoning and logic or executive function might be more profoundly affected than others depending on how one acquired it.
With IQ there's a theory you have fluid intelligence and crystallised intelligence. I'm wondering if she had greater deficit in the expression of one over the other or if they were both diminished equally. You could argue that if she had a low IQ and a rubbish upbringing she had very little crystallised intelligence to draw from in terms of children and parenting. What good experiences could she build upon? How could she problem solve?
If you have a less than favourable upbringing, you can can make up for it using your intelligence to learn and observe different ways of doing things. If your IQ were low, and you found it incredibly difficult to learn and extract new more positive child rearing information it would be far harder to do better as a parent, plus young children aren't easy to understand.
I can imagine the frustration must be huge trying to work out what a demanding toddler needs on the hop daily. It calls for intellectual dexterity and lateral thinking at times. And lets me honest, MN is chock full of parents with no cognitive disabilities, who are finding it extremely difficult to cope with rearing young children.
For someone with such limitations, as Star's mum, losing patience and violently lashing out, awful as it is, would be expected. Add a demanding sadistic partner, hurting you, mentally abusing you, and telling you it's because you allow your daughter to get away with perfectly normal things toddlers do, and threatening to leave you, unless you deal with her/him and it's almost inevitably going to end badly.
ULTIMATELY SS let her and Star down. She really ought never to have been able to keep the child without close observation and the mandatory involvement of trustworthy family. She's now in prison for a wholly avoidable tragedy had she had intervention from day one.
The doctors, health visitors, midwives, and ancillary healthcare staff, let them down. I know of several people in real life who weren't even allowed to leave the hospital after giving birth without a confirmed SS visit and they had less confounding issues than Star's mother did. I'm amazed actually, as I know the difficulty some of those people had getting SS out of their lives, and they were ultimately decent parents.