I have a 10 year old cat that has been the only cat in the house for several years. I have a couple of 12 week old kittens outside (they have access to the heated garage). One of the kittens has gotten pretty friendly and has come in the house a couple of times. My senior cat is afraid of the kitten and runs and hides as soon as he comes in. Any ideas on how to get her to accept the kitten? I'd like to bring him in more but I don't want her always hiding.