The biggest barrier for women and defining their abs is actually losing stomach fat to see them. In order to find them, you have to burn stomach fat. This translated into changes in your diet to cut those stubborn pounds in your stomach area, and a disciplined nutritional plan that cuts bad fats to keep those toned abs exposed. Sugar, sweets, fried foods, and junk food snacks need to disposed.
After you achieved fat loss in your midsection, you still have to build muscle to get that attractive, defined abs look. This will take time and training. No gimmick, fad diet, or miracle pill can do what discipline and persistency will produce. You don't have to build a ton of tissue to show off, but no muscle will have you looking more like a pancake and less fit and defined.