I've read that sweat lodges are a detox therapy. The rash *could* be from that, if you had heavy work outside. But, the quinoa could be the issue too. I'd not eat it again for at least 6 months. Gut healing takes at least that long, I believe. I'm sorry to say.
Yes, when we open our detox pathways, we could be processing more stored toxins through breastmilk, even. However, by eliminating the undigested proteins (due to leaky gut/intolerances) we are lowering the toxin load to baby, concurrently. She is probably loving your yummy milk.
With nutrient dense milk/nutrition, we can detox toxins, even baby can.
Personally, I'd wait at least 6 weeks to consider the top four, corn, dairy, soy and gluten. If you have eliminated other foods, I'd consider adding them in a couple of weeks- one at a time, after resting your gut and increasing gut healing supplements (CLO, kefir, etc). I would start adding bone broths, green juices, liver too, when you feel up to tackling another step. Just take it slowly, make lifestyle changes for your health, rather than overwhelming yourself trying to do everything at once.
It is common for kids to go through binges and strikes about food preferences. I'd just focus on finger foods. We make a "buffet" here with a myriad of alternatives, some nutrient dense, some just yummy without additives (like homemade oatmeal chocolate chip cookies with coconut oil and pecans). I offer many options, rather than "meals".
The Bubbies is in the refrigerated section at the grocery. At Earth Fare, not our mainstream grocery. And the dill pickles or sauerkraut are naturally fermented and have probiotics.
Glad you are feeling better!