When we got our latest kitty, Mau Mau, we kept her in a seperate room for one night, then let the cats take turns being in the living room, den, and kitchen. The next day, they all got used to the scent of the new cat being in the house. The next day, we put Mau Mau in a cat carrier and set her in the middle of the living room. The other cats did the usual hissing and growling. We put her back in her room and repeated this the next day. By the third day, the cats were playing pawsies under the door. We brought her out in the carrier that night for awhile and then let her out. No hisses or anything, they were all chirping at each other and now, they are all best buds. It just takes a little time. So glad Winnie is home!!!