She and Sirius actually get along really well.
(Look in the upper right hand corner, you will see Tobi sniffing Sirius. Too cute!)
The lady at the pet adoption place told us it would probably take a few days for her to warm up to us, and to not introduce the dog and cat for a few days. Well, within an hour of having her home she wanted to explore the house. So we decided before letting her out of Tammy's room we would see how she and the dog got along, knowing that there were plenty of places for her to hide in there if she needed to. Well, let's just say, within minutes both animals were laying on Tammy's bed perfectly content. They really like each other and have even nuzzled up to each other. Tobi seems right at home too. She loves it here and within minutes of getting here was purring up a storm. She is a loud purrer too. I can hear her from across the room. She likes to nuzzle your nose with her nose, and loves to play! She is a great addition to our family.
Tammy actually named her. My only requirement when she picked the name was that it had to be a Harry Potter name. So she chose Tobi. Tobius Snape is the muggle father of Professor Severus Snape. Since the kitty is a girl we couldn't name her Tobius, so we went with Tobi. We also considering other names like Calli (short for Callidora who was a relative of Sirius Black and married a realitive of Neville Longbottom). We also considered Minni (short for Minerva McGonagall, who was of course a professor who transfigured into a cat), Tali (short for Natalie McDonald who is the only actual person to be in the books -she was a 9 yr old fan of JK Rowlings who passed away from cancer. So JK Rowlings honored her by writting her into the books) and Tonks who is one of our favorite characters from the books and movies. We considered other names as well, but ultimately, Tammy chose Tobi.
I think it fits her well. ;o)