Hi Daniel,
Frankly at 13 years of age she should be seeing a vet twice a year for senior check-ups. It could be anything, but by her behavior I fear she is in pain. Self diagnosing is a risky business , we are not experts. I would just take her to an emergency clinic TODAY!
They will examine her and take some tests. That is the only sure way to know what is going on with her. Obviously she wants your attention--something is bothering her.
Please keep us posted, K?
CML
I agree with Opus. Also, when your in question about your cat's health ask yourself-Is she eating more/less than usual? Drinking more/less than usual? Has she lost/gained weight? How long has this been going on? Is she sitting in unusual places for her? Is she hiding?
If you've noticed a change in any of those things, then something is definitely wrong and a vet visit is in order. BUT, if this is a problem with urinating, this is a medical emergency. If she can't urinate, the bladder could rupture.
Best wishes to you! Please keep us posted.
is she peeing OK? ....many cats that age get FLUTD..a urinary tract obstruction due to crystals in their urine. put her in a room alone, with a litter box food and water than monitor to make very sure she is passing urine ok, or else this is a medical emergency....its very painful that why the meowing. if she has not passed urine today and the meowing continues please take her to an emergency clinic and get her checked out. good luck poor baby