Lots to think about here and something like "amygdala hijack" may indeed be relevant to JS in the interview materials available.
I suppose I'm less interested at this point in what she said in those interviews and how she said it than in the established pattern of facilitating "co-sleeping" with, then allowing and even sending MS to sleep with SS alone for what seems to have been years.
It's a bit like the hot-car death in AZ -- the backdrop pattern suggests a level of complicity with at least the risky behaviour that contributed to a fatal outcome, if not directly contributing to it, with the additional factor in MS's case of a long, profoundly disturbing history of SA that seems not to have registered with JS (or, if it did, bothered her overly).
For me, this a classic instance of paying attention to what was done and largely discounting what was said, especially in the aftermath. But that's not to discount the forensic interest in JS and the now well-documented oddities and divergence of her actions from her descriptions.