Breathing rates may change for a variety of reasons and in some sleeping positions the airway may be slightly occluded which may result in altered breathing but without examining Kiki I cannot say for certain whether it is something to be concerned about or not. As for drinking, some cats may drink less that are on a wet food diet but you should ensure that she is keeping hydrated; you should visit your Veterinarian for a general check about the breathing and they can also check the hydration too. Regards Dr Callum Turner DVM
The slight upturn to the corners of the mouth make Russian Blues appear to be forever smiling. Members of this breed are generally polite, quiet, and well-behaved, for cats. It’s quite easy to teach them to stay off counters and out of off-limit areas; usually a simple “No” will do. However, Russian Blues seem to think politeness should go both ways and take offense at being made to look silly. A dignified cat, Russian Blues can be trusted to know when you’re making fun of them—and they won’t soon forget this breach in manners, either.
If your cat is having difficulty breathing, this can be a life threatening emergency. It is important to have your cat seen by a veterinarian as soon as possible. You will need to give a thorough history of your cat's health, onset of symptoms, and possible incidents that might have preceded this condition. During the examination, the veterinarian will carefully observe how your cat breathes, and will listen to its chest for evidence of a heart murmur or fluid in the lungs. Your cat's gum color will be carefully evaluated as well, since the color of the gums can indicate whether oxygen is being delivered to the organs (hypoxemia) effectively, or if it there is a low red blood cell count (anemia). Your veterinarian may try to get your cat to cough by pressing on its windpipe. If your cat is having extreme difficulty breathing, the veterinarian will give your cat oxygen to help it breathe before doing any more tests.