Jazzy, If you're doing a single protein/single carb food, maybe you could achieve the same results with a home-cooked diet? Or use treats that are the same protein and carbohydrate with no other ingredients added?
I feed Booker a food with a single protein source and a single carbohydrate, and I feel his quality of life is quite high. He loves dinnertime, he loves morning time, he loves nap time, walk time, fetch time, etc. Of course he loves food and getting snacks, but if he had his way and ate whatever he wanted, he would be overweight, and that would be more weight for his hips and knees to bear every day, and it would also shorten his life span. But there are treats that seem like they would be compatible with Veronica's single protein/single carbohydrate diet...
For example if she could ONLY eat herring and sweet potato, well, they do sell dehydrated sweet potato dog treats, where it's just sweet potato, no additives. You would have to find them at a more "natural pet" type or boutique store. Booker likes them.
Herring's just a fish, and dogs love stinky fish! You can buy herring whole at the grocery store/meat market, cook them and debone, or freeze them for a few weeks and serve raw. You can also get canned herring (try to find low-salt varieties) to feed as a treat, in a Kong or whatever.
If it's duck, there are duck-jerky treats that contain only duck breast jerky. And I'm willing to bet you could find some venison jerky, possibly intended for human consumption, that didn't have a huge amount of salt added if she was on a venison diet. There are so many kinds of unique treats out there from all kinds of animals, perhaps one will match up with the food?
I'm not sure if these ideas are actually compatible with the diet (Miss Kiwi?) but hopefully it helps.
And if it helps you any, I'm sure that Veronica, while she loves treats, loves her mom more. You might be more upset than she is about not being able to feed her treats or snacks... she might be just as happy if you act jolly and unconcerned and play a good rousing game of tug, or go on an extra-long work, or play hide and seek or fetch or something... but if you're upset I am willing to bet she'll pick up on your emotions. Think about the long run, if you can identify what she's allergic to, it will benefit her quality of life long-term, no more itching constantly for days at a time, no more runny poo emergencies, no more blisters or hives, for far beyond twelve weeks.
In addition you can take some of the kibble away from the meal times, set it aside to use during training as little bite-sized training treats?