It's funny that Diane Burpdog posted right before me with her goody list, since I was planning to say that Diane converted me years ago to her philosophy of letting an elderly dog with a poor appetite eat whatever it will eat, within reason. And reason can get pushed beyond anything you or the dog previously dreamed of.
I think smelly food helps stimulate the appetite. But if you're concerned about salt, my standard appetizers of canned tuna or deli meat are high in sodium. As are hot dogs.
Just brainstorming -- could you cautiously experiment with feeding her something a little salty to see if it stimulated her drinking?
Weight -- my Eve flirted with pudginess as hard as she could for most of her adult life. After reaching 11-12, she dropped a few pounds to just under her racing weight and kept it there. Probably lost muscle mass in her back legs. She looked pretty good.
Dental -- maybe talk with other folks who actually know her, including a vet who has seen her a time or two, and look at her holistically -- weighing the pro's and con's?
Smooches to the gorgeous girl.