maybe she is still struggling a bit to get used to the high protein. my kitten (6.5 months) cannot handle it just yet it seems. If you are worried phone the vet. you can also try some digestive enzymes and i found plain yogurt really helped too. ( i give Roland about 1.5 teaspoons a day, sometimes a little more when he really asks nicely
)
(although i have to add that i dont know much at all about diabetic cats)