Chowda!
When our beloved Truffles went to kitty heaven, we decided to get a new cat. Specifically a young male (so he'd both get along with Rosemary + get used to Mia)
After stopping by several animal rescue places without success, we finally went to the place with Don McQuinn's granddaughter works & she hooked us up with a funnest cat I've met - a white cat with black spots that we immediately named Chowder.
Chowder & Mia became best mates instantly. They play together all day. Chowder sleeps with Mia & Mia enjoys grabbing Chowder under the arm pits & carry him around the house (whether Chowder actually enjoys it is highly unlikely).
Mia has also successfully (no, really) trained Chowder to be on a leash. We tied the leash to the extension cords so he has a wide range. In fact as I'm typing this Chowder is off in the backyard chasing bugs while tied to the cords.
Rosemary was initially, er, very cool - ok - hostile to Chowder. But after a few weeks she has definitely grown to at least accept Chowder, and we've even occasionally seen the two playing together. I guess giving hold Rosey a young male to play with was the right thing to do.
We love Chowder & welcome him to our family.