Yes, nutrition is a VERY hard subject to learn. It has taken me years of studying/reading/saving notes/etc to scratch the surface. Add to this the fact that each species has a different dietary ecology and you end up with A LOT of stuff you need to learn... But, thankfully for us, nature is thrifty and although they all have different natural diets, they can be 'grouped' into African, Australian and South and Central American species when it comes to a very generalized concept of their dietary needs.
Now, you shouldn't be giving her calcivet if she is eating pellets because pellets are made so they provide always the same level of vitamins and minerals (which is not what nature intended for birds as they are all seasonal feeders) and they already have both D3 and calcium so, if you are giving her calcivet on top of the pellets, she is getting way too much (and D3 also ends up in the liver as fatty nodules -precursor to fatty liver disease- because it's a fat soluble vitamin that nature decreed should be made in the body and not ingested).
I don't know what the 'complete' physical involved but, in my personal experience, avian vets never do a bile acid test unless one asks them to (they also never do ionized calcium, test for iron in the blood or even do full body XRays -not the best way to see if liver or heart are enlarged but enough so it gives you a good idea if you should explore further with an ultrasound) so it would behoove you to see exactly what the vet did and what the results were (I always ask for a copy of the results they get from the lab -we have a saying in Spanish: four eyes see more than two)
I don't know how to make the recipe easier (I am an old grandmother who cooks without recipes) but I will give it the old college try
. Take one cup of kamut, one cup of oat groats, one cup of hulled barley and one cup of red rice and adding twice as much water as there are grains (meaning, you put all the grains in a largo pot and then add enough water so the water not only covers the grains but is over the grains by the same distance from the bottom of the pot as the grains are -if the layer of grains is, say, two inches deep in height from the bottom of the pot, you should add enough water so the water level is two inches above the top of the grain layer). Turn the heat high and, when it starts to boil rapidly, stir it a bit (to mix all the grains together evenly), cover the pot and reduce the heat so it simmers (meaning, it's not boiling hard but it has a little tiny bit of bubbles coming up very slowly) for about 20 or 25 minutes (watch the water level halfway and add more if it needs it because you do not want the grains at the bottom to burn). Cook half a cup of millet and half a cup of quinoa separately but following the same procedure only adding a little bit more water (they 'suck up' more because they 'grown' more) turn off the heat under the pot at around 10 minutes (they cook very fast because they are so little). Once both 'batches' are cooked, mix them together and allow to cool (if the pots still had water in them, drain the grains by dumping them into a pasta colander first). Once the mix is cooled, add the veggies without thawing them: get frozen corn, frozen peas and carrots, frozen chopped broccoli and frozen cubed butternut squash. Do not get the frozen sweet potatoes unless you are planning on cooking them because they need to be soft enough so they kind of 'break up' and some of the 'puree' that came off the pieces covers the grains and veggies (this way you ensure she is actually getting sweet potato even if she doesn't go for the little chunk of it). Add about two tablespoons of flax seed and VOILA! Gloop! Then all you have to do is freeze daily portions in baggies or some other way (some people who have only one bird do it in ice cube trays and take one cube a day to feed their birds but I like baggies better).
It is your decision, of course, but I would eliminate the pellets altogether and feed her only fresh (wet) organic food for a while because when one is faced with an animal that has allergies or intolerances (I've rescued dogs and cats as well as parrots for many years and have more than my share of 'mystery' reactions - I have a dog that can only eat salmon, no grains, no beef, no chicken, no lamb, no nothing but salmon and sweet or white potatoes) the cause of which cannot be specifically figured out, the best thing is to change EVERYTHING. Going by what you have posted, she has had more than enough vitamins and minerals for quite some time so I would put her on a cleansing regimen: everything organic, no extra vitamins/minerals for a few weeks (she has had more than enough for quite some time so this is not going to hurt her in the long term and might even be what makes the difference), organic aloe vera juice and liver and kidney cleansers and tonis (as I recommended on my previous posting). I put all the new birds on what I call the 'detox regimen' when they first come because people tend to overfeed some stuff and underfeed other so the regimen helps their bodies kind of find their own balance so they can start 'afresh'. I recently got a bluehead conure that is over 24 years old. Elvis came in lethargic, with an overgrown beak, dull eyes, etc (even my daughter could tell the bird was not well just by looking at it) and you should see him (I am not sure it's a him) now: bright and fully opened eyes (he squinted before), clean plumage (he bathes everyday now), flying around (he could not sustain even horizontal flight and he now can manage vertical flight) and vocalizing normally (the bird did not even make a peep at dawn or dusk) and the ONLY thing I did was to put him on the detox regimen and daily multivitamin/mineral (he wasn't getting any) for four weeks (I don't normally do four weeks but he was in bad shape) and then on the same diet my other birds get.
Try giving her gloop and raw produce for breakfast and just two or three small tree nuts for dinner (human grade and roasted) it and see what happens but please note that when you talk about any kind of allergy or intolerance, you do not see improvement in a matter of days and, sometimes, not even weeks because the histamine that is released into the bloodstream from the reaction to the allergen or irritant takes time to dissipate (flying would help a lot with this).
Also, no warm showers, no hair dryer, no touching her without washing your hands first (for things like cream, perfumes, nicotine, etc) and people food (NOTHING!). No nothing but organic food especially made for her and cold baths with spring water (same for drinking) because you need to eliminate ALL potential sources of dietary and environmental causes for the itch.
Let me know if this helped.