I agree that it's possible she could have fed her guests foraged mushrooms, seen them get ill as a result, panicked that she'd accidentally given them death caps, and then destroyed all evidence and lied to police about the source of the mushrooms. It would make her a terrible human being, for leaving the people she 'loved' to die instead of providing doctors with the information that could possibly save their lives, but it wouldn't make her a murderer.
What doesn't make sense is that she still maintains she was unaware any of the mushrooms in the beef wellington were foraged. She genuinely thought the mushrooms came from Woolworths and the Asian grocer (which she was unable to name). If you think all the ingredients came from supermarkets and if your guests then become seriously ill from some unknown cause, why would you immediately dispose of your food dehydrator at the tip? It makes no sense. Why assume it was the mushrooms that made them ill rather than the beef or something else they'd eaten? She's tried to explain it by saying that Simon had accused her of deliberately poisoning the family with dehydrated mushrooms, but he denies ever saying this (and I'm more inclined to believe his evidence over the woman who lied about having ovarian cancer).
Also, in this scenario, if you're going to panic about anything, surely you're going to panic that you and your children are going to die or get seriously ill. Yet she seemed curiously relaxed about that possibility, and more concerned at getting her kids to their activities the next day. She claims to have fallen ill after the meal (which there is absolutely no medical evidence for), yet she discharged herself five minutes after a doctor warned her that she might have death cap mushroom poisoning. Then she tries to explain this away by saying she discharged herself against medical advice soon after giving birth to her son. Well, 1) I doubt she was in serious danger of dying that time and 2) If she hates hospitals so much, why has she booked herself in to get gastric bypass surgery?
There's also the photo of what look like death cap mushrooms on the kitchen scales. The iNaturalist searches on her computer showing the locations of death cap mushrooms nearby. Her phone records being consistent with having visited both of those areas soon after. Remotely wiping her phone while it was in the possession of the police because she's curious to see if it's still connected to the internet. She didn't get ill despite eating the same meal. Her kids didn't get ill despite eating the leftovers with the mushrooms scraped off...
If she's found guilty then we're going to hear all the details of her alleged previous attempts on Simon's life, and any doubts over her guilt will be gone.