Unlike Disneyland, Universal Studio Tours are not for everybody. While there is plenty to do & see, the attractions are not appropriate for all ages. This should be strongly considered if you are planning a family holiday that includes Universal Studios.
There are no attractions that are suitable for babies or toddlers at Universal Studios. Most babies and toddlers will not be interested in the Universal Studios Tour. Furthermore, getting a stroller almost the upper and lower lots is almost impossible. Universal Studios is a great place to have some fun - unless you are a baby, a toddler, or a parent of a baby or toddler.
If you will be taking your vacation with a toddler or a baby, you may be better off saving the Universal Studios Tour for another vacation - a few years down the road. There is no charge for admission for babies and toddlers at Universal Studios, but there usually isn't if the person cannot enjoy the attractions at the park! Remember - the baby or toddler isn't the only one who won't be having any fun.