You can try adding a bit of fennel tea to her food to calm her bowels. I’d also get a stool sample to the vet and test for parasites such as giardia, unless you’re feeding very cheap kibble or varying her diet a lot. Because what you’re describing sounds extreme. For comparison: I have two dogs and “babysit” five others periodically. Still, I experience dog gas no more than maaaybe once a month or so. And even then it’s mild, happens once, and is over after a bathroom break.
I’m not sure what it means to be working on changing a dog’s diet. Are you saying she isn’t tolerating any of the food you’ve tried? Because then, you might want to get her checked for allergies. If you just aren’t sure what kibble to get: any high-quality dog food will eliminate that issue immediately and for good. If she’s picky: a cheap and simple way to make kibble more exciting for dogs is to stir in a spoonful of babyfood or unsweetened applesauce/yogurt.