Welcome to Pet Talk.

How big is Macy? What kind of dog is she?
I would try taking them somewhere out of the house to get to know each other better. Neutral ground is always better.
My 9 year old chihuahua, Buster, wasn't too thrilled when we brought home our 1 year old Pug, Nacey. But he got used to her after a little while, and now they will sleep next to each other. My 6 year old min pin, Charlie on the other hand loved Nacey from day one. Even though there is a 5 year age difference between the two of them they got along great from the start. I also have a 4 year old pomeranian, Bitsy, who couldn't care less either way.