I had a Cert III course to complete and intended to get into when DS was really little (like newborn) but we had lots of unexpected problems early on which made it a very low priority. I didn't get into it until he was about 5 or 6 months old. And picked up what I needed to complete at a time when DP was home a fair bit on holidays so he sorta just took over with DS most of the time.

Its hard but not unachievable. I have a friend who went back to a law degree with 3 kids, the youngest was 2 months old