That last pound (like the last 5 pounds in humans) is the toughest! Since she has lost weight (very good job on your part!), she likely needs fewer calories now. So you will need to decrease the amount you feed a little more.
What kind of exercise is Tink getting? Increasing her exercise a bit more will also help her "power past" this plateau.
She is doing very well. We walk every evening, and a couple of days ago we extended the distance. In the beginning, she could only walk half a block and very, very slowly. She has arthritis and a disc problem in her back. Since losing the weight, she walks a good four blocks and trots! She gets tired and has to stop and rest a few times. I let her set the pace. It appears that since we extended the distance, the weight loss may have kicked in again! Thanks for your help and interest. By the way, because of the arthritis, I think I will buy her an orthopedic bed.