Development progresses very differently depending on many factors. There are typical developmental milestones that one might expect children to achieve at particular ages.  Because each child’s development follows a unique trajectory based on a variety of individual and environmental factors, the development of specific skills and abilities will happen over an age range.  For example, a child might begin walking at nine months, or not until closer to 18 months, depending upon their particular temperament, context, and caregivers. . You can look to additional resources such as the CDC’s Developmental Milestones to help you understand the typical development of children in your care. However, it is important to take the time to talk to parents about their child’s development and to not jump to any conclusions based up on what is considered “normal” or “standard” development. Particularly during the early childhood years, there is a broad range for development and children reach milestones at varying rates.