Agreed. Stress, pain, and infection can all raise BG quite a lot, and it sounds like there's definitely something else making her unwell, so it seems fairly likely that you're going to continue to see unexpected numbers moreso than with a "normal" transition (which still has a lot of ups and downs) until you're able to figure out what else she needs help with.
No a great answer, I know, but I have high hopes for something coming from the upcoming vet visit. Just hold the dose of insulin and that's the best you can do on the BG front for her for now, though I'm sure it feels like you have your hands tied.