Can a short girl get washboard abs?

Currently, my daily routine is 20 minutes of Zumba, 30 minutes of Pilates, and then my 8 min abs and 8 min legs videos. I do all this four times/week. I watch what I eat. Today was a very average day so it's a good example. I had 2 eggs and two slices of toast for breakfast. One slice of toast with butter for lunch, and a pork sausage and mashed potatoes for dinner. I cook everything without oil in the oven. I just use a little bit of butter to cook the eggs. I'm about 5 ft tall, 21 years old, and I've been trying to get abs for the past 4 years and still not. I'm in great shape, but there's this layer of fat over my stomach muscles that just never get's worked away. Any advice?