Leah, this is not normal for any animal at any age. She is straining to urinate. This could be due to bladder stones, inflammation or infection, but it could also be due to a cancerous growth in her urinary tract. It would be important to take her to the vet and have her examined and have the urine analyzed. An ultrasound evaluation of the urinary bladder could quickly rule out stones or tumor of the bladder. I hope it is nothing serious. Keep us posted and know we are here if you have further questions or concerns.