I find that with infants my Sims have to be reset at times as infants would get stuck in the floor or to the other Sims. Resetting the Sims usually fixed the issue, or leaving the lot and coming back, but it does take away from gameplay when the infant is stuck to my Sim's foot.
With toddlers I have found that my parent Sims are constantly adding "check toddler" or, "pick up toddler" or, "put down toddler" to their list of actions autonomously and it results in them running back to wherever the toddler is. This happens even if the toddler is happy and being cared for by another Sim. This autonomous interaction takes time away from my Sim and is added between actions I selected. I also find that my Sims really need multiple interactions and supervision to actually teach toddlers, feed toddlers, or anything really to do with toddlers otherwise they cancel the interaction, even if the toddler is starving or dirty or needs affection. However when I don't ask the Sims to I frequently find they have stuck the toddler in the high chair and wandered away.
Today I had the mother Sim queue up a numerous actions, but she continuously adds "check infant" or "put down" infant Sim (infant is always already on the floor or in a crib) randomly. Even if I cancel the action in her queue, she walks all the way to the infant before cancelling the action. In one instance another Sim on the lot was actively having tummy time with the infant when the mother Sim tried to interrupt to "put down" the infant Sim. In another instance, the mother Sim successfully put the infant in the crib and went downstairs to autonomously crochet. I cancelled that and told her to knit, selected an object... and then my Sim went back upstairs to "put down" the infant Sim she just put to sleep. Frustrated, I shift-clicked and reset the mother Sim and then she went back downstairs to knit. Before even making it down the stairs she autonomously queued up "check infant" which I cancelled. The infant's only low need is sleep and they are in their crib.
The other adult Sim in the household is not related to the infant and never autonomously checks on nor puts down the infant Sim.
