Hi Sunnydelight! I have never had a c-section, however since your ab muscles have been cut, it is understandable that it will take a bit longer for them to come back. Other things to consider are your age, how many pregnancies you have been through, how may c-sections you have had, and of course your genetics. These situations will play a big role in how long it takes to get your ab's to fully respond to your efforts.
As long as you are eating a healthy and balanced diet, doing a weekly strength program( up to 2 but no more than 3 full body workouts) and varied cardio exercise (3 to 6 times per week) you are doing fine. I would also suggest that you do 3 to 4 very focused ab workouts per week (about 10 to 12 minutes sessions). Vary the ab program so that you challenge your muscles from multiple angles. Incorporate a stability ball for variety too. Good Luck!