Hello Figi's Mom..and welcome to the FDMB

We know Chief's name... What would you like us to call you?
You've come to the right place. Most here have been home testing their kitties a long time, using human meters. There's a slight difference in calibration from the veterinary Alphatrack meter, but it's all relative. Your kitty's BG is low if it's below 50, and too high if it starts drifting above 150 or more.
Dry food isn't a good feeding choice for cats, although some vets still haven't gotten with the program. Change takes time, and vets don't have a lot of free time, so they depend heavily on the pet food industry and pharmaceutical companies to tell em what's what..and that doesn't always work out.
Cats are obligate carnivores..that means they were designed to eat almost entirely meat. So corn, wheat, and other grains, as well as vegetables, can eventually cause long term damage. It's just like us humans and the modern diets we eat..Pizza, ice cream and french fries might taste good, but they can put us on the road to heart disease, obesity, and diabetes. And just like the companies that make human food..pet food manufacturers spray a coating of animal digestives on their dry food products..it makes them taste like what they're eating is fresh meat..but it's a disguise designed to fool the palate.
Cats aren't programmed to drink a lot, either, so when they're on dry food, they are surviving, but only just, because they won't drink enough to properly digest the dry stuff, until their organs are so deprived that they become damaged. They don't 'remember' to drink enough water.
A good cat food is at least 75% water. quality cat foods, that contain enough water and are plenty nourishing without being super expensive like the prescription diets. What you want to shoot for is a wet canned food that is 6% to 10% carbohydrates.
There's also some here who feed raw diets, have had great success with them. But before you run out and buy a grocery cart full of chicken legs, find out from the raw-food folks, how that food must be prepared.
Sometimes you get creative and try to spice up the 'undesirable' food. One member here crushes up Pure Bites freeze dried chicken pieces..that have a *crunch* that is very like the consistancy of dry food. (Actually I think it crunches better.I just got some and my furkids love it....it's very light, crunchy, and no carbs!)
But if you are on a budget or in a hurry, and need something to tempt Chief now, try crushing up some dry food and adding it like croutons on top of the wet food. You can even puree the wet food, and make it the consistancy of soft ice cream. That trick worked for me. Most cats love parmesan cheese, the kind most people use on our spagetti. It's stinky and strong flavored...since your cat is now considered 'elderly' she may not have a great sense of smell..so the stinkier the better. But remember..you might have to touch some of the food to Chief's lips so he can get an idea of how it tastes..lots of cats won't even recognize that wet food is food. My cat Gizmo often balks at eating something new..until I've wet my finger with it, and smeared it on his lips. Gently scruff him so he can't pull away, and smear quick with just a little bit of the wet food. Then immediately let him go, don't hang on to him..and let him think about it a while.
Can you tell us more about Chief? It will help the folks on this board, to help you. How was he diagnosed? Does he have any other health issues? Are you currently giving insulin now, or are you just working with his diet.
You said Chief was 13...does he still have all or most of his teeth?
My kitty Dottie is 13 too. I thought I would have zip/squat/zero/nada chance of success with home testing, but once you accidently stick your own finger with a lancet, and squirt yourself in the eye with a mock-up dose of fake insulin, it's a snap.
(just kidding 
it's really easy) The first hurdle is learning to do an ear prick to check glucose levels. You can get Chief to tolerate this by first fooling with his ears just a bit, but no poking. Just give his ears a rub, and give him a protein based treat. Rub his ear again, and give his reward, even if it's a tiny piece of dry food at first..because in the beginning, whatever works, gets the prize. Later on you can get him so that he'll just come running for a chin scritching.
Pretty soon he'll be excited to get all the attention. And you can start to accustom him to a prick from a
very tiny, skinny needle lancet, fine as a human hair. You'll be on your way to becoming a home tester. And you'll develop a bond with your cat that will be far closer than the one you already have.
Now that you're loaded down with possiblities, will be a good time for you to poke all around the Forums. Everyone is very eager to help. Again, welcome.
Here's to you and Chief living many more years together!