Hello and welcome to Just Answer. I am a licensed veterinarian and would be happy to answer your questions.
When you say you see her breathing, do you mean there is more of a respiratory effort?
Is more of her abdomen moving with each breath?
Any kind of changes in breathing in a cat who is hiding out more than usual and not eating as much is concerning.
The reason I say that is that cats are so good at hiding their illnesses that by the time you are noticing signs, they are often sicker than they appear.
Her being a little older cat only adds to my concern.
Her symptoms are somewhat non-specific and could be due to abdominal pain or could be due to changes in her lungs. Breathing abnormalities can sometimes indicate fluid build up in the lungs consistant with heart disease. Pulmonary disease like asthma can also cause similar signs.
Since this has been going on for a few days already, I would difinitely not wait too long to have this evaluated. I would recommend that you schedule her for an exam with your vet soon.
Yes, did you get my reply?
Thats OK, the chat mode sometimes loses replies.
Do you have any further questions?
Good luck with her.
You are welcome.