This is a common question from parents with kids like yours, whose birthdays are near the cut-off date by which the child must reach a certain age for school enrollment. These dates can vary greatly from state to state (anywhere from July 31 to January 1). Since development is a gradual process, and each child progresses at his or her own pace, there is no "right" answer for all children.
Things to Consider When Making the Decision:
When making this decision, you should consider how your child behaves in a variety of environments. It is a great idea to speak with other caregivers, such as a preschool teacher or a frequent child care provider.
If the kindergarten your child would be entering offers a readiness assessment, you can use that as one measure of school readiness. Keep in mind that these assessments tend to focus on academic skills—there is no one best measure of how ready your child is for school but it can be helpful to take into account both academic and social and emotional readiness. Your pediatrician is also a great resource, since he or she has tracked your child's development through well-child visits.
Consider many aspects of your child's development. Questions to consider might include:
How does she react in environments with lots of other kids her age?
Can she pay focused attention to a task or story for 10 to 15 minutes at a time?
Can she listen to instructions?
Can she communicate her needs to others?
Keep in mind that kindergarten may have changed quite a bit since your time in the classroom; there now tends to be a more rigorous schedule. You might want to ask to see a sample school day schedule for kindergarteners, or even spend some time observing a kindergarten class, if that is possible.
You Know Your Child Best!
After gathering and considering all of this information, listen also to your intuition as parents. Do you believe that she is ready to thrive in a shared learning environment or that she needs another year with more unstructured play and time for further social and emotional development? You know your child best!
Additional Information from HealthyChildren.org: