This is Dr. Christian. Perhaps a little more information can help me help you. When did the weakness start? Are there any other symptoms such as excessive drinking, excessive urination, vomiting, diarrhea, weight loss or lack of appetite? Does you cat have any other medical conditions or on any other medications for something else? Is is indoor or outdoor?
No she is a indoor cat. Every now and then she seems to have problems jumping up on the bed or sofa like her hind legs are not very strong.
She seems to be eating alright. Not sick that i can tell. No other medical conditions.
Weakness in the rear legs can be due to several different conditions. For instance, arthritis. While arthritis is not as common in cats it does happen. Diabetes is also a condition that can cause weakness in the rear legs but is usally accompanied by weight loss plus increased urination and thirst. Heart disease is also possible. I would recommend having her checked by your veterinarian. Your vet will start with the exam, looking for soreness, listening to the heart and palpating her whole body. Then the next step may be x-rays or bloodwork depending on your vet finds on the exam. If you have any other questions just respond back to this message.