Hi! What you have is a diastasis. Im sure if you google that word, you will get some sites that can tell you how to repair it. Basically, the muscles separate during pregnancy b/c of poor mechanics (sitting straight up from a lying flat on back position, like on the OB's exam table) in combination with the relaxin hormone. Once they separate, you need to bring them back together so they can act like a girdle & unless you fix it, the crunches won't do much.....& may make the separation worse. It can also lead to problems down the road...lower back pain, hernia etc
What you can do.......lie on the floor on your back with a towel or long blanket around your waist. When you lift your head, like you do in crunching, bring the 2 ends of the towel over each other, so that you are pulling it snugly around your torso. This will help bring the separated muscles back together. You can also do the same thing but using your hands to bring them together. Also, try to be mindful of pulling your belly in during the course of the day, maybe at stop lights when you are driving.
I think a good post partum dvd would help too...to you make sure you are doing core exercises that take the diastasis into consideration.
You have taken the first step, which is figuring out that you have one (most women don't even know about it) & now you can fix it...& you can fix it!! Do you know how large your diastasis is? If it is very wide, you may need extra help, but don't run straight away to surgery. Some can be fixed with exercise ! Don't be discouraged!!!! All the best!!!!