You could opt to make them happy with cheats.
How I did it for a family of 2 adults Sims and 6 kids:
I would have one Sim make big meals, and every morning we would go through a routine of toilet, shower, eat, watch TV.
All did different things so they wouldn't get in each others way. At night we would go though the same routine, just added homework and sometimes had them work on skills.
I did this until they all grew up. However we didn't have toddlers at that time, which are pretty hard to control in my opinion.
It's mostly routine, doing the same thing every day.
