It looked like a temper tantrum of a two year old to me, and I couldn't take it seriously.. Most of the problems stemmed from her childish attitudes: refusing to eat cold lentil soup, instant mash and Spam in spite of being so hungry; making an enormous deal out of doing a bit of cleaning, then screaming orders at John, telling him to go and tell Stephanie what to do, practically in the same breath as castigating him for telling others what to do on an earlier occasion.
That said, I am wondering if the extreme behaviour was caused by low blood sugar.. Diabetics can go into meltdown mode when their blood sugar drops. She'd been refusing food all day, which would have meant that her blood sugar was unnaturally low, so stuffing herself with pizza and wine would have sent it rocketing, followed by a sudden plummet when the body insulin kicked in. The fact that she was craving more wine could actually have been because of her blood sugar level being extremely low.