Hey Lumifan,
I'm a fan of strength training, and I do like weight machines and hand weights--but I'm not a big lifter--I just like to keep my muscles toned, and it has made a difference in my belly.
Be sure you do the right kind of ab training, though, because when a woman has had children, there are some additional issues. Maybe post in the Exercise forum or Ladies Who Lift for tips.
Those resistance scales--the body fat percent varies with water weight, so they are not accurate from one time of day to the next. But, compared with me, your body fat percent is good, although it could be lower according to the book that came with my scale. (I also use a resistance scale.) Mine is around 33%, and I'm still "overweight" on BMI and body fat percent. (When I started, I was around 44%
)
So, it's not that you are carrying a lot of excess fat. Toning will help--and also, just waiting it out for a year or so to see how much your skin will tighten up on its own.
Jay