I don't have a Kenyan. I do have a rosy - although that hardly makes me qualified to answer definitively.
The general rule is that the prey should be about as big around or tad large than the widest point of your snake. My rosy is a bit bigger than that, and on fuzzys. She should probably move up a step. She is now bigger around than they are.
Just give it a try, if the sizing looks OK - I expect it will be fine. Not that much nourishment in pinkies.