Running, swimming, HIIT exercises will all reduce fat off your tummy.
I've got pretty good abs (lots of kickboxing/gymnastics when I was younger) my physio couldn't even get a pinky between my muscles after birth BUT you can't see them because I still have fat on top of them.
Get your heart rate racing, sweat and eat well.
DH, Me and our two boys.
Lost our little squirt 20/11/13.