who needs weights?

the kids play wonderfully for the hour that i'm doing my aerobics (there is always the little interruption of wiping noses or bottoms but it's worth it!) until i get on the floor for the last few minutes to do the crunches. it never fails that no matter what bailey is doing, she stops and comes over and straddles my stomach. it has to give me some more resistance and burn more calories, right?