She is hissing and growling after three days at foster but it is just shock.

She was raised with a dog.

The foster says she can however pick her up and she calms down and purrs in her arms.

I am not super cat savvy by any means. But it would be cool to get to know this new cat for 6 months heavy work on her and with her and billy.

UPDATE

I just looked at the rescue who contacted me with this special need kitty (very senior) and they say INDOORS ONLY NO EXCEPTIONS for all their cats. I would be okay with an indoor only cat (though I dont see why leashed sitting in the yard is bad at all) but hubby leaves the doors open when he goes in and out and often for quite a while. This cat would be upstairs for a month I think and then let to explore everywhere downstairs with slow introduction to billy previously. I dont know what to do. This organization makes a point of saying indoors only. I should not take the cat they sent me.