Has anyone seen my abs?

I knew I wouldn't be in the best shape after having three kids.  I have come to expect a few more lumps in places both welcome and unwelcome.  What I did not expect after having three kids was that I wouldn't be able to do one measly sit up.  How am I ever supposed to get my abs back in shape if  I can't even get off the ground to do one sit up?

As you can guess, today was my first attempt at working out since Gabe was born.  It really stemmed from a moment a few weeks ago that went something like this:

I'm nursing Gabe in the back of the van while waiting for some store to open.  I don't bother covering up in front of the kids, and no one can see me with our tinted windows in the back of the van. Out of the blue Alie points to a roll of 'skin' (think fat) on my side and asks "What's this Mommy?"  After a few seconds of thinking about how to word this correctly without either 1. giving her an idea about bad body image, or 2. letting her think its ok to be overweight, I said "Its extra skin and fat that Mommy has left over from having Gabe.  I am going to start working out like Daddy does to get rid of it."
A few days later Alie sees me nursing again and says "Mom, the skin is still there, you really need to start working out with Daddy."

Sigh...she's so right. So tomorrow I start a step class that runs three days a week, and on my off days I'm going to do the Ab ripper from P90X with Mike. Today was my first P90 experience, and I didn't expect much, but I literally could not do one regular sit up.  It's like my ab muscles just didn't work. It didn't hurt, they just wouldn't work.  I was able to pull off some of the leg lifts and side sit ups, but regular sit ups...no way. Hopefully one day I'll get them back through hard work, but for now, if you see them, please let me know.