And as we understand it, despite the internal havoc, completely undetectable after 48 hours.
She never intended for that toxin to be found. Nor for her victims to survive OR to give witness prior to their deaths. Individual wellies, dead with them. In fact, what they ate, long gone, untraceable, flushed, many times over.
Her (dark) "genuis" would look like this IMO.
All four would consume the deadly toxin, they'd get sick, rebound a bit, then die. Would never bother with the hospital, thinking they could wait it out at home. They'd die, toxin would not be detectable. If EP was tested at that point, it would be undetectable in her too, so she could claim the same stomach bug and they'd be none the wiser.
And her motive would be buried. Who kills four people just to hurt one person? Who kills anybody over perceived slights? Who kills two people with whom one has no problems, just to kill two others? Who would do that? Someone with a hidden agenda, that's whom.
What about stealing beloved grandparents from the children? EP supplied that as a defense iirc, why would she do that to the children? Right, a normal person wouldn't. IMO EP WAS done with them, they wouldn't take her side, wouldn't tell SP to do as EP desired, so she rused to kill them all. If they children knew how she'd been "disrespected " (in her head), she predetermined that they'd side with her. IMO EP had a HABIT of making sure they ALWAYS sided with her. Manipulative, triangulating, covert popularity contest.
IMO EP thought she'd figured out the perfect crime. A disappearing weapon.
But when the hospital went straight to mushroom poisoning and then death caps, she had no plan for that and IMO sverige thst followed was a mad scramble (panic indeed) to erase all traces of DC, which is the EXACT OPPOSITE of omg could I have accidentally used bad mushrooms?
Nope, she made a decision. To bin evidence of DC and fully deny being the source of it, accidental or otherwise.
Because the evidence was overwhelming, IMO her defense decided it best to admit she was the source of the DCs, which they could only do by putting her on the stand, and then try to convince the jury it was by pure accident that BW's containing undetectable PIECES of DC mushrooms, contained dehydrated and powdered DC toxin, as if.
All that hiding mushrooms in her kids desserts, never one used the accidentally acquired, conveniently powdered DCs? Never once popped a bit of one in her mouth to test to make sure "nothing happened"? No prior tainted meal with powdered DCs? Not even a quick test as she prepared the duxelle and, having found it bland, added powdered mushrooms to taste, but didn't taste it again?
In the months she had dehydrated DCs in her house, she didn't even one time use them in any of the ways she might normally use mushrooms, until THAT day....
Her intent is revealed in her cover up.
JMO