Maybe try the Virgin Diet, eliminate the top 8 allergens for a month, then slowly re-introduce.
As for your M and MIL, if they don't respect the way you want to feed your kids, you don't have to let them feed them :P
Stumbled into Primal due to food allergies, and subsequent elimination of non-primal foods.
Start Gluten-Free/Soy-Free: December 2012; start weight 158lbs, Ladies size 6
Start Primal: March 2013, start weight 150lbs, Ladies size 6
Current: 132lbs, Ladies size 2
26lbs lost since cutting the crap.