This shocked me because I was about to give up and either allow Kitty to possess the little girl, in which my party's favor would drop dramatically (I believe it was -10 for Leliana and -15 for Morrigan), or simply reduce the difficulty level to easy, which was not even a fair fight. Instead, I had my party drink up some spirit resistance, which really didn't help that much anyway, and have the whole party attack one minion at a time.
What was amazing is that I had no healing of any kind. All my health potions had been depleted. So I assumed I would have to go back and return later when either my party had leveled up or I had a ton of health potions. Now for the shocking part. While combating the lesser demons, all of my party quickly died off, including Alistair, Leliana, and Morrigan. All died but one, my dog, before I even began the final fight with Kitty. So it was just my dog vs a full-health Kitty. Honestly, I almost reloaded my last save before waiting to see what would happen. I didn't expect to last more than a second, but my hound kept biting a Kitty and dodging every thing that was thrown his way. He wore Kitty down, and finally won after a few minutes. This was, by far, one of the most interesting and surprising fights I have seen in this game so far. My entire party was no match for Ms. Kitty, but my hound not only survived but took her down at the end. I should have known that when it comes to hound vs kitty - hound wins!
Too bad this thread is over a month old. I really wanted to share this with someone.