I lucked out and don't have much ....flat stomach .... I would guess the worst area is my arms. FYI, exercise does nothing for loose skin. Of course the loose skin may look a bit better as it sags over harder muscles. We will all be different when it comes to loose skin. It depends on age, how many times pregnant, where we carry the weight, sun exposure, how much excess weight we have .......
In my case, I carried my excess weight all over. I am 47 years old and have quite a few years of excess sun exposure. I was only pregnant one time in my life and only gained 19 pounds. I now weigh about 2 pounds less than I did the day I delivered my son (who is 5 years older than you). I feel great with my results. At my age now, I would look too thin if I lost any more weight. A BMI of 24 is a good place for me. I don't need any plastic surgery.