Part of the answer to this depends on how far post-partum you are.
There are some basic exercises that can set the framework for recovery when done immediately after birth. If you’re still breastfeeding, the hormone Relaxin is still present in your body which makes ligaments loose and will impact your exercise options/choices.
Restoring your core is based on restoring the “normal” that was lost during pregnancy. We breathe, stand, and move differently when we’re lugging around a growing baby. The muscles not only stretch apart, they also stop communicating with our brain in the same way as their function changes. So, the connections have to be re-learned as a first step.
Hope this helps! 🙂