My fourth and youngest child just turned five and should be starting kindergarten in the fall. Except maybe she won’t. Or maybe she will. I’m still trying to decide.

For the fourth time, I have a preschooler not ready to move onto kindergarten.

You would think by my fourth tour-of-duty of preschool I would have figured out how to prepare a kid for kindergarten. Seriously, I’ve been at this preschool thing for 11 long years. That’s long enough to see the Gen X moms replaced by the Millennial moms replaced by the Gen Z moms. But not long enough for me to figure out kindergarten prep.

Kidding aside, as any good preschool teacher would tell you (and I have known quite a few), kids mature and develop the skills they will need in kindergarten at different rates. Even with a quality Pre-K program and a mom who has spent way too much time thinking about kindergarten, some kids are just not going to be ready for kindergarten on time.

Academic redshirting is the practice of keeping a child who is age-eligible for kindergarten out of school for an extra year. Educators call it the “gift of time,” giving your preschooler the time needed to develop the level of social, emotional, and cognitive readiness needed for success in kindergarten.

It’s a really tough decision. You need to think down the line, not just kindergarten. Do you want your child to be the youngest (sometimes by as much as 18 months) in junior high? Do you want to send a 17-year-old off to college? Do you want to have a 19-year-old high school senior at home (and on the parental payroll an extra year)?

I’ve been through this decision-making process four times and have picked up some valuable information along the way.

Before I start, please note that I am not a teacher or any sort of education specialist. I’m just a mom using Google (and a lawyer, which is why I included a disclaimer). For guidance on your child, you should talk to his or her teacher or another education specialist.

What exactly does your child need to know and be able to do before kindergarten?

Gone are the days when kindergarten was half-days filled with play. Kindergarten is serious business. By the end of kindergarten, kids are expected to be well on their way to being proficient readers.

Here are some of the factors my daughters’ preschool teachers have used in determining kindergarten readiness:

• Does she get along with her classmates?
• Can she write her name?
• Does she know the alphabet?
• Can she recognize letters?
• Can she identify the sounds that letters make?
• How high can she count?
• Does she speak correctly most of the time?

Who is redshirting their children?

Despite what you read in your mom Facebook groups, the vast majority of children are not redshirted.

According to recent article by Diane Schanzenbach, an education professor at Northwestern University, and Stephanie Larson, a long-time preschool director, only 6.2 percent of children are redshirted, with college graduates twice as likely to redshirt their children as high school graduates. Even among kids with summer birthdays, the vast majority of them enter kindergarten on time.

What have I learned from my research?

Redshirting is generally not worth it.

In the early school years, there definitely is an advantage to being older. Older, more mature students initially score better on tests than their younger classmates. But by the end of elementary school, this advantage has all but disappeared.

Why? It turns out kids learn more when in a challenging environment. Learning and competing with older students helps younger students make greater academic gains. Children greatly benefit by being close, but not too close, to the limits of their ability. They learn not from getting all of the answers right, but by making mistakes and correctly them quickly.

What about social and emotional maturity? As any mom with multiple kids will tell you, younger siblings mature faster thanks to interactions with older siblings. Frequent interactions with more mature classmates can help kids mature faster.

Did I redshirt any of my kids?

Borrowing an analogy from baseball, I’m two-for-two.

With Daughter No. 1, I frantically signed her up for a variety of “kindergarten prep” classes, like reading readiness and a handwriting clinic, determined to send her to kindergarten on time.

She went and was miserable. For the first three years of school. Three really long years of spelling lists and early readers she could never master.

It turned out that she was dyslexic, something I had suspected all along. With a diagnosis and a great private tutor, she flourished and quickly went from not being able to read basic Dr. Seuss to reading Harry Potter.

I sent Daughter No. 2 to school on time too. Academically, she thrived on the challenge and flourished. Socially? It was a little bit of a struggle, but she eventually got where she needed to be (but not without a lot of tears, both hers and mine).

Daughter No. 3? She has the latest birthday of all her sisters. After experiencing her two older sisters crying in kindergarten, I decided to hold her back. BUT, and this is really important, I was always on the look-out for ways to challenge her. She didn’t just bide her time in preschool—she went to a transitional kindergarten designed to get through the first quarter, maybe even first half of kindergarten. There were many trips to museums and libraries and we read lots and lots of books together.

She had a great kindergarten year and continues to do well in school.

Now I’m up to Daughter No. 4. Thanks to Daughter No. 1, I’m well-versed in the signs of dyslexia and I suspect she may be dyslexic. I’m planning on having her tested for learning disabilities and will wait and see where she is in July before I make a final decision.

Four really tough decisions, but at the end of the day, after you have talked to teachers and consulted experts, it all comes down to using your best judgement. No one knows your child better than you do.