Okay. Before you read this, it comes with a warning: Humor is in the eye of the caretaker. Read with an open mind.
Many years ago, I had a Siamese cat. His name was Trouble and he was an indoor/outdoor cat. At the end of a very long night at work, I came home to find Trouble very angry with me that he was stuck outside. Very angry. I let him in, fed him and then fixed myself some dinner. I plopped down in front of the TV to unwind. Trouble proceeded to yell at me about being left alone for the day. And if you have ever heard a ticked Siamese, you know they can yell. After listening for awhile, I reached down and picked him up, hoping that he would quiet down. As I pet him, my hand came away covered in blood. Long story, even longer, he had been in a fight. We found a vet who would see us at midnight on a Friday. They did surgery and put a pin in his hind leg. Trouble healed well and you could never see any sign that he had ever been hurt. Unless I ticked him off. And then that ornery old cat would limp like you've never seen a cat limp. He would actually drag that hind leg as he walked. And he would keep limping until he got what he wanted.
Fast forward to the point of this story. Mom feels great all of the time. Seriously. She's healthy. No major issues. But, do not ignore her or deny her something that she wants. If you do not give her what she feels that she deserves, Trouble's limp reappears. She moves like she's on her death bed. She does everything short of throwing her wrist to her forehead and moan. Oh, wait. Yeah, she adds that sometimes. But, just as soon as you give her whatever it was that she wanted, the pain magically disappears. I just hope that she continues using the cat box as well as Trouble did.