Overwhelmed by cat food!

Hey all, I apologize if this is covered elsewhere on the site, but I have been searching for hours now and I am trying to see if there is an easier way to narrow down all the cat food brands out there. Ruby is turning out to be a picky eater. I have her on mostly wet food and want to use dry food to supplement her meals while she is still a growing girl. I've been giving her Wellness canned food which was the first brand she would consistently eat without trying to bury but she has developed pretty loose stools on this which at first I blamed on the wet food introduction but it hasn't gotten any better in the last 2 weeks. Now I think it might be a sensitivity to fish as most of the varieties I've been giving her contain some kind or another. So now I'm giving her only the chicken and while her stool consistency has improved, it is still not completely solid. So my plan now is to just go back to the store (found a Holistic/Organic place nearby) and grab some cans of Tiki Cat, Weruva, Nature's Logic, and Nature's Variety Instinct that have no grain and no fish in the ingredients. Hopefully she'll like at least one of those brands. However I'm still having trouble finding dry food. She got Purina, I think the ProBlend? while being fostered, however I am trying to at least find something again grain free, fish free, and by-product free that breaks the bank as little as possible. I've given her Blue Wilderness and Wellness Core but she turned her nose up at both and now I am at my wit's end trying to find what to try next. Can anyone think of a brand of dry food that is fish free that you would be comfortable feeding a 3-4 month old kitten? Preferably one that is also grain free but I realize it might be difficult to have everything I am asking for. I will take any recommendations you have into careful consideration.

Thanks in advance!

~CheshireKitty & Ruby

P.S. I did try switching her foods gradually, but she would eat so little of it that I gave up after awhile and just let her have the Purina so that she gains weight appropriately for her age. I've read that kittens are supposed to eat a lot and she just doesn't seem to eat much at all. If I've missed any important details just let me know and I will gladly post them in a reply.

Grain free diets are not the be-all and end-all. Most kittens will eat Royal Canin dry and canned. I foster many little ankle biters and they all thrive on it. That being said, I just had a little guy do very well on Solid Gold, but that can be difficult to find. My current foster kittens are eating the Royal Canin Kitten dry and a variety of good quality cans, including Natural Balance and Performatrin.

Orijen dry is excellent

The best dry foods I know of are Wysong Epigen 90, Young Again Zero Carb and Ziwipeak, but they are not cheap.