Each time I had an infant in the household I had to turn off autonomy because it's just really bad game design to have other Sim (stupid) autonomy override my commands for anything infant related.
Like recently this infant is hungry, so I had a Sim put her in high chair to explore food. Right before she eats, she calls her father from the bathroom to pick her up for what???? YOU ARE ABOUT TO EAT OR BE HUNGRY. Then the Sim that I re-tasked to feed her goes idle because another Sim from TWO STORIES down autonomously "Check Infant" and cancelling the autonomy ALSO cancels the task I assigned to the other Sim. C'mon devs.....