There are some mild exercises you can do for tummy seperation. You lie down and try to push your belly button through to the bed. (they may have shown you this one during pregnancy, if it was diagnosed pre-birth). Even at 6 weeks, the exercises don't get that much more physical, you just trying to strengthen all core muscles. The DRAM often comes back together with no exercises too!

No sit ups and protect your back and tummy when leaning down or picking anything up.