Toddlers are great weights

When my daughter was younger I used her as my weight system, and I was in the best shape. I'm tempted to have another child just for this reason. Here are the exercises that I did with her. Maybe you can add them into your routine. We would have "fun time" and it started with I would lay on the floor and bend my knees to do crunches. She would sit on my lower abs and I would do the crunches and give her a kiss every time I got up there. She wasn't allowed to lean down to me. I had to be the one to kiss her. This helped me maintain my posture during the crunches. Then I would hold onto her waist and let her sit on my lower abs and pull myself up in the air using my abs so that my shoulders were still down on the floor, but my torso was at a 45 degree angle. I would go up and down slowly and my daughter loved to ride the "elevator". Then I would lay down as if I was going to do a push up and I would push myself up, but instead of going back down, my daughter would climb up on my back and lay down. Then I would hold in that position for as long as I could and then slowly go back down to laying flat on the floor as the "air was coming out of the mattress." I also used to do wall squats and pretend like I was sitting and my daughter would sit on my lap. The last thing I used to do was I would hold her in front of me and have her wrap her legs around me and I would do squats. When I got down to full squat position, she would flip backwards and try to touch the floor. If she couldn't touch the floor then I didn't squat low enough. She would then pull herself back up and I would go back to standing position. To a kid, these are just fun games, but to a mom they help you lose the baby gut and give you back the pre-baby butt.

All mom's I know with small kids have GREAT arms!
Liz