We got Yum Yum at 2 months old shortly after bringing her home my husband wanted a burman kitty so we found one for free. She is 6 years old or so. At first you keep them separated for about a week to two weeks then let them be around each other when you are at home. There was some hissing and growling but not actually fighting. That only lasted a short time. Now they are the best of friends and keep each other company while we are at work.