Barbara gave a good rule of thumb to follow on feeding. I'd increase her morning allotment of food (and yes the large rocks and or a ball in the dish do help slow one down with the gulping); maybe a bickie (cookie) around lunch, and then increase the evening meal.
The Raw diet, well these days it can be a lot of things. Raw chicken wings, whole grains like brown rice, raw fruits and vegetables is one menu that some folks use. I suggest doing an internet search on BARF (bones and raw food) diets and you'll probably get hit with more than you wanted to know.
Today it is possible to order prepackaged raw diets which are not any more difficult to feed than kibble bought at the store.
Debbie