How old is Miss Cali?
Princess Kuhio was a very small cat (6 pounds). When she was 16, she developed a hyperthyroid. She ate and ate and ate and continued to lose weight. Might be time to go to the vet and get her levels checked. They can do a simple blood test. We gave Kuhio medicine every day and it helped a lot until she was killed (it was not related to her thyroid).

Also, does Cali drink a lot of water? That could be a sign of diabetes.

Keep us posted.