Keeping Secrets From Your Co-Parent

Q. My 11-year-old daughter started her period and asked her mother not to tell me. So, she didn't. I found out almost two months later, and I was not happy about the secrecy. Isn't this something my ex should have told me, even if our daughter asked her not to?

A. This is a sensitive situation that sits right at the intersection of a child's growing need for privacy and a parent's responsibility to co-parent transparently. To be direct: yes, your ex should have told you. Not sharing this information establishes a quiet "You can trust me more" dynamic with your child, and that is questionable co-parenting.

Let's start with what matters most. Your daughter has reached a significant developmental milestone. Puberty isn't just a physical change; it's an emotional one. For many children, especially at 11, asking for privacy isn't about secrecy or exclusion. It's about trying to regain a sense of control over a body that suddenly feels unpredictable and exposed. And yes, part of this is simply that you are Dad (and a guy), and she likely felt embarrassed having that conversation with you. That's not personal. What made it personal was that Mom chose not to tell you.

To be fair, your co-parent was placed in a difficult position. She may have believed that honoring your daughter's request was the same as protecting her confidence. But here's the distinction, and remember this, because it will come up again:

A child can ask for privacy.

A child cannot set the terms of adult co-parenting.

Menstruation is a health and developmental event that affects medical care, emotional support, and day-to-day parenting. Withholding that information, even with good intentions, undermines the co-parenting alliance and unintentionally places the child in the middle. It also gives an 11-year-old control over the flow of parental information, which is not a role children should ever have to manage.

Here's the difference in approach now that you're divorced. If you were still together, your daughter would likely have confided in her mother, and Mom might have said to you in passing, perhaps while watching television one evening, "By the way, Lily started her period, but she's a little embarrassed to talk with you about it right now." Most dads would understand, respect the moment, and not make a fuss, because they were included.

After a divorce, however, that same moment can shift. What once felt like sharing an intimate parenting responsibility can turn into a feeling of superiority. When parents are together, shared information protects a child's privacy. When parents are apart, withholding it can unintentionally turn that information into currency: "I know more about our child than you do."

Withholding the information is supported by misguided reasoning based on a fear of invading the child’s privacy. That fear, unfortunately, is reinforced by the back-and-forth lifestyle. Both parents may worry, “If I don’t honor this privacy request, my child will never trust me again.” That then morphs into, “She won’t want to come back,” or “She will prefer the other parent.” And now co-parents are keeping secrets from one another when they should be comparing notes.

Here's the nuance. Your ex didn't need to share details, commentary, or your daughter's emotional processing. A simple, neutral heads-up would have honored both roles: "I wanted you to know that our daughter has started her period. She's adjusting and asked for privacy, but I felt it was important that you be aware." That approach respects your daughter's dignity and your role as a parent.

As for how you handle this now, resist the urge to confront your daughter or express hurt to her. That would ask her to manage adult emotions, something collaborative co-parenting cautions against. Instead, focus on restoring safety and openness. You might say: "I know your body is changing, and you may want some extra privacy. You don't have to tell me everything, but I want you to know I'm here to support you, and I'm not uncomfortable talking about these things if you ever want to."

Separately, address this with your ex, calmly and outside your daughter's presence. Frame it around co-parenting, not blame: "I understand why you wanted to respect her wishes. Going forward, I need to be informed about major health and developmental changes so I can support her appropriately."

But there’s more. What does her mother say to her when your daughter finds out that she did say something to you after all? The key here is to make sure the child does not believe they can control the flow of information.

I’m in favor of being honest and direct. “Honey, of course, I respect your privacy, but I will not keep this from your dad. This is very natural and normal, and sharing the information is not about privacy; it is about keeping him informed about your health. We both love you and want to be available when you need us.”

This approach is an important component of collaborative co-parenting. It focuses on adults communicating and coordinating with each other so their children don’t have to carry that responsibility. When parents handle their children's milestones together, their kids feel protected at both homes rather than exposed at one and protected at the other. Sharing responsibility sends one clear message: We both love you, and we are both here for you.