We have several cats led by a robust 5 year old castrato, they all have grown up with each other and get along together The Boss cat has grown up from a tiny kitten and regards our house as his territory but he is happy to share with the other younger cats.
Our Granddaughter has come back from university bringing her year old femail persian which has grown up without interaction with other cats since sne was a kitten and spending most of her time in granddaughters flat, so she is wary of all humans except granddaughter
Our cats have all tried friendly approaches and been met with hostility, same with humans with the exception of granddaughter.
How can we integrate this hostile stranger? Serious suggestions please.