I have an 11 year old female domestic short hair cat. She has always been a very good cat non aggressive. My son brought in a 5 week old kitten and the 11 year old is always hissing when the kitten gets too close. We put them together only with supervision because I am not sure if my older cat will attack this small kitten. How can I make this transition as easy as possible for my older cat so she will accept the kitten. I am just afraid she will hurt the kitten if I left them to themsleves.