Hi, Ive been working out with my partner for a little over a month now with ab workouts. She is 18 years old, 5 feet 2inches and weighs 110 lbs give or take 2-3 pounds up or down. As far as I know she doesnt have any health issues. She already has a flat stomach, and eat healthy. She is also an athelete, so she is physically active most of the time. I started her off with two 10min ab workouts twice a week. We bumped it up to 15min abs twice a week, then it became a Monday-Friday daily activity. We have even bumped it up to 30mins straight ab workouts with no break, once a day, except weekends. My question is, how can i get her stomach to become more toned, instead of just flat?