Diastasis Recti workouts

Any suggestions for ab workouts when just getting started??? I'm 6 weeks pp and just got the ok to be active again. I'm pretty sure I have diastasis recti. This is my third baby with the oldest almost 4 and all have been over 8 lbs. I had to change my diet for other health reasons, so I'm actually 15 lbs under my pre-pregnancy weight from my last baby. Now I just need to do something about this belly.