It's important to have realistic expectations when introducing a new pet to a resident pet. Some cats are more social than other cats.
Slow introductions help prevent fearful and aggressive problems from developing.
Confinement Confine your new cat to one medium-sized room with her litter box, food, water and a bed. Feed your resident pets and the newcomer on each side of the door to this room. Don't put the food so close to the door that the animals are too upset by each other's presence to eat. Gradually move the dishes closer to the door until your pets can eat calmly, directly on either side of the door. Next, use two doorstops to prop open the door just enough to allow the animals to see each other, and repeat the whole process.