I don't think this is glucose toxicity. She hasn't been on the recent dose overly long. Although, earlier on, you held the 1.5u dose for some time (8/27 - 9/22). I suspect the yellow numbers are related to how she's feeling. If there's an infection, give the antibiotics some time to work. Do you know whether these ABs tend to upset Dolly's stomach and if so, you may want to start probiotics. Just give the probiotic about 2 hrs prior to the AB.
She's probably eating the fish flavors because they are smellier. You could also try to put the water from canned tuna or the oil from sardines on her other food..
if the numbers stay elevated, just keep systematically raising the dose. If she does need steroids, it's not the end of the world. There are many cats that need to be on steroids for a variety of reasons. We work the insulin dose around whatever the medication is that may raise the insulin needs.