Although, the conventional suggestion is to wait at least six weeks after delivery to begin exercise regimens. We still advise you to consult your doctor, like other postpartum body decisions. When your doctor says you're good to go and you're ready, then there is no means to wait.
"Regular training in the form of a core abdominal workout can enhance the integrity of the muscles and minimize the degree of separation in certain individuals with minor diastasis." most effective during the first 6 to 12 months after delivery." - cores doctors.