I used to when our daughter was small. Started with a childseat on the rear rack and front panniers for assorted child-related items when she was a year old. The commute was about 8 miles to the daycare and then a couple miles back to where I worked and involved a pretty significant hill between the two. When she was 4 I switched to using our tandem after modifying it with a clamp-on bottom bracket mounted partway up the rear seat tube to allow her to reach the pedals. Both approaches worked fine, but she did have a tendency to want to start conversations or ask for snacks right at the steepest part of the hill when my spare breathing capacity was limited. She's now an MD so this was back a few years.