Actually you can get "flat abs" from dieting alone. What is liposuction? Liposuction is a surgery that removes fat. What does dieting do? It uses a calorie deficit to make your body catabolic, losing fat. Plenty of people have six pack abs simply by being very skinny. The pictures that say, "loose skin, must be liposuction," are ridiculous. Liposuction gets rid of fat quicker than dieting and would cause loose skin much more, but dieting also does cause loose skin. Since you lose fat slower on a diet than liposuction, the skin has more time to stretch to the right shape, but loose skin is still completely normal.
anyway...I wouldn't doubt that she has had liposuction