Every age range comes with its own set of challenges and nuances. With the infant and toddler stepchild, you won't have to deal with a child talking back, but you may need to interact more frequently with the other biological parent than you would if your stepchild were any other age. Infants and toddlers can be a handful. If you do not have children of your own, learning how to handle an infant or a toddler may seem overwhelming. If you do have children of your own and have been through the infant and toddler years, you may need to be extra careful that you don't impose your own ideas about parenting onto the child or other biological parent.