A suggestion, from a mom to another mom. Add as much activity into your regular workout routine as possible. And include the kids. like long walks,hiking, swimming, etc. Not only is it fun and quality family time. But it'll help you get back in shape and help your family, especially kids learn to lead active lifestyles.
My whole family, husband, dogs, kids, etc...take a long walk in the evening every day to the park by our house and play with the dogs. On the weekends we spend as much time outside as possible. My kids have more energy (although, sometimes I think that isn't a good thing)and hardly watch tv or play video games anymore, my husband has more energy and motivation. He's joined my gym. Which helps me because we workout together and push eachother and my dogs love it and are in great health.