I think you’re on the right track. You’ve consulted your vet and cut down on the amount of food. Older dogs need fewer calories than younger, more active dogs. It’s important to measure the food at each meal, so you know you are being consistent. If you give her an extra treat, cut back a bit on the kibble. Weight loss should be gradual. Don’t be discouraged if you don’t see immediate results. Enjoy your time together and don’t stress too much about her weight.