Hi, I'm A 58 Year Old Woman Who Has Always

Hi, I'm a 58 year old woman who has always been very trim and fit. I still wear a size 4 (25/26) pant and weigh around 110 at 5'3". I eat protein, veggies/salad, very low carbs, avoid deserts most of the time, but I do like my cocktails and wine. Is this why, even though I walk/run/hike & workout at the gym at least 4 days a week, I still have a small layer of belly fat?