Walking is good for so very many reasons, including trimming the waistline (mama's gotta lose the "baby weight") and simply improving your health. You just feel better after walking. You actually might be inspired with more energy and willingness to tackle other projects after your daily walk! Not to mention, the baby might fall asleep in the stroller, and the little kids may go down better for a nap later on.
Take a break. Go enjoy yourself! Your children will enjoy it too. Point out the squirrels, the birds and their chirping, meet the neighbors as you go! A daily walk will do everyone some good.