Dear parent, I know this is a big topic. You may see yourself as an ally to trans people and still be shocked and not know what to say. Or you might actively oppose transgenderism. However you may feel about this, know that your child has just shared something that was probably scary for them to talk about.This is an opportunity for you to imprint into their brain, the message that you love and accept them no matter what. Your kid will remember this event. They may or may not identify as trans forever, but your reaction will stick. You may be shocked, terrified, angry, confused, upset. You are absolutely allowed to have your own feelings and process around this, but for right now, send a clear message that you are glad they feel that they can come to you to talk about this deeply personal experience.
Throughout your child's teen years they will do, think, and feel things that you do not like. If you send the message that they can't share things that you don't approve of, they will only learn to hide their thoughts, feelings, and actions from you, and likely from others as well. Not only does this damage your relationship with them, they may also learn that their authentic self is unlovable. You may think that they aren't really trans, that they're just confused and following a trend, and that if you don't accept them as trans, they will eventually "snap out of it."
It is possible that your child might not identify as trans forever. Lots of people fluctuate in their experience and expression of gender identity. And yes, I would guess that confusion is part of their experience simply because being a teenager is confusing, not to mention exploring identity, gender, sex, sexuality, and cultural norms that may or may not fit with a teen's developing sense of self. This doesn't mean that their experience is untrue or invalid. Exploring identity in any form involves self awareness - a healthy skill, especially for the rapidly developing mind of a teenager. It is also common to feel incredibly clear about gender identity, even from a very young age. Again, the most important thing is that you help them understand that you will listen to them no matter what and that your love does not depend on their experience of identity.
After you've made it clear that your child can come to you to share their inner experience, take space to process your reaction. A therapist, and/or support group is ideal. A therapist will have an outside perspective and be able to help you look at what specifically is coming up for you. It's common for parents to need to grieve the loss of their expectations (whether or not your kid is trans). Individual therapy gives you the space to talk without filtering yourself so you can work through any grief, fear, anger, or confusion that might come up. A support group with other parents of trans teens can also help give you the experience that you're not alone in something that might feel confusing and isolating. Process your reaction with your own support network, rather than with your child to give yourself space to do your own work and to maintain the clear message that you love and support your child no matter what.
Once you've spent some time processing your reaction, (and this will likely be an ongoing process) talk to your kid. Be curious and non judgmental. Let them know that you are there if they want to share more. If they're open to sharing, asking them open ended questions like the following can help you understand their experience better, while helping them feel supported as they work through their feelings:
"How has it been for you to know that you're trans?"
"Who else have you told and how did that go?"
"How did you first know that you're trans?"
"What are your preferred pronouns (don't assume that they're he or she. Your child might prefer he/they or she/they, or any other combo).
"How do you feel about yourself when you use your preferred pronouns?"
"Is there a gender affirming name that you would like to use?"
Finally, as you continue to process your own evolving reaction that likely changes with your teen's changing self expression, educate yourself. There is a lot of information out there about gender identity, gender roles, and what it means to be trans. Learning about gender identity can do a lot to alleviate fears. It can also be helpful to learn about the difference between sex and gender, and the ways that gender norms have changed throughout time. One of my favorite examples of this is that as recently as the 1950's, the color hot pink was considered a "boy's color," while soft blue was associated with girls. Check out the resources below for information about sex and gender and supporting trans youth.
As it becomes safer and more socially acceptable for people to come out as trans or non-binary, more and more teens are exploring their gender identities. Supporting your trans teenager can bring up a host of emotions, but there is a way through it. Be gentle with yourself, know that it is common to have reactions that you may not like to see within yourself, and support is available.