She is part of your family now it is common for cats to have multiple 'homes' what is not common is for your other cats to accept her ...........My male cat disappears every couple of days and stays gone for a day or two but always comes home clean and well fed On the other hand my little female goes ballistic when any other cat trys to come in the house it drives her nuts since our house rull is any cat can come in through the cat door and eat Velcro will just sit there and mad dog them and then hisses at me if I pet them