Hello and thanks for trusting me to help you and your pet today. I am a licensed veterinarian with over 25 years experience and would be happy work with you.
It is difficult to say if she is trying to die, but there is a very good chance that she may be experiencing some degree of organ failure at this point and at her age, the most common organs to fail are the kidneys. When the kidneys fail, it can lead to anorexia and weight loss and sometimes GI signs as well. Of course there are other disorders that lead to weight loss and anorexia, but kidney failure is one of the most common. Older cats are in a very fine balance and it doesn't take much for that balance to be upset and cause them to stop eating. Sometimes, with a little supportive care, like fluids, we can get them back to a good quality of life, but it is difficult to say without at least an exam.
I would have your veterinarian perform a physical exam and after that, they will have a better idea of it is more humane to let her go, or if there is a chance with a little care, she may still be able to enjoy some time here. I know this is a difficult decision, but getting a little more information from an exam will make the decision easier.
I hope this is helpful. Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please reply so I can clarify for you.
My posted replies are for general education only and not meant as a diagnosis. Only after a thorough veterinary examination can a diagnosis for your pet be made and specific treatments be advised or medications be prescribed.