Give the ruling, given the possibility she was truly alone, is it possible that her Rxs, intended to salve her anxiety, exacerbated it? Super human strength and the combo, fueled by Ambien, should be filed with the crazy effects some users/patients report?
Over time, warning labels found their homes on these medications, warning of preposterous behaviors and increased suicide risk.
Could it be that the mystery murderer in the sealed house is the medicine cabinet?
Could that cocktail of Rxs have pushed her anxiety over the banks and introduced suicidal/homicidial ideation where there had not been? Pretty sure that warning already exists, but for young adults who are prescribed them. She was older than a young adult but who's to say the meds (going on or off or somewhere in between) didn't do exactly that in this situation? A case if the treatment being more deadly than the disease.
I think the meds (again going on or off and while taking them) are responsible for her increasingly disordered thinking (that everything hinged on 1st grade grades) and therefore could provide the explanation for how a pleasant school teacher went from not uncommon anxiety to a frenzied attack. Biomechanically impossible, somehow upended by biochemical hulkdom.
Just Me and My Opinion, looking at this situation from the perspective of no foul play.
JMO