T.S.
A.,
I am an Exercise Physiologist specializing in prenatal and postpartum fitness and the owner of Big Belly Fitness. i have developed a workout that is designed to help get the abdominals back in shape after baby(ies). The issues that cause the "mommy tummy bulge" relate to the entire body. You need to make sure you're doing abdominal work properly as well as stretching the chest, strengthening the upper back, stretching the lower back and hamstrings. This combination will improve your posture which will in turn get everything back where it should be.
It looks like you might be located in the city and unfortunately the classes I teach on the topic are mostly in the Western Suburbs. A good place to start is to get a large resistance ball and sit on it as much as you can. While you're sitting on it, tighten your abs and release them back and forth. Make sure to keep your head up and imagine your belly button pulling in to your lower back. This exercise will start building the transverse muscles that are needed as the foundation to rebuild your midsection.
If you want to e-mail me directly I can give you some more exercises to build on from there. You'll really want to make sure you work the area the correct way because doing ab exercises improperly can actually make the situation worse. Good Luck and don't hesitate to drop me a line.