I don't personally feel 3x a day is necessary for adult dogs but if you want to do it, and it works, that's fine.
Why don't you just feed her first meal earlier, and then her dinner? Or if you're going to do 3 meals, just split the raw up... give them the same amount but in 3 small meals, instead of two. I don't think you should give them more food than recommended or they may fatten up real quick
As for kibble, Solid Gold is pretty good. It's made at Diamond Food Plant which is worrisome for some. You can get Wellness now at Petsmart and they make a small bites. Fromm is excellent food and really tiny kibble, so is NV Instinct.
Why do you think Acana is too big for them? Are they having trouble chewing it? If they're not, I would continue with Acana. My friends 4 and 5 1/2 lb yorkies eat it fine
Good luck! I know how time consuming and worrisome the food thing is. haha.