How old does your child have to be to know their true gender?
There is no set age. Most of the Transgender people I’ve worked with over the years knew as young as 4 years old that they were really the other gender. A small percentage did not know till later in life and some knew they were not the natal gender but didn’t feel exactly to be the other gender either. There can also be some confusion in a child about their gender and the confusion can last a long time. It may be that over time the child will come to feel themselves to be one gender more than the other and it may be that the child will feel more comfortable somewhere between male or female, or even shift back and forth. It’s also possible for the child’s confusion to be a reaction to feedback and wishes of the parents or other adults close to the child to be the gender they were born into.
What things might a young (under 5 year old) child do or say about their gender?
They might say things like “I’m really a girl”, or “I’m really a boy”, or wish for long hair, or not to have a penis (in boys). They might ask when they will be “fixed” or if a “mistake” was made when they were born. They might want to dress as the other sex and play with toys typically associated with the other sex.
When signs are visible, natal (born as) boys might wear a towel or shirt to simulate long hair, might want to play dress up as a princess, play with dolls, wear sparkly shoes, and berets. There are also many transgender (male to female) adults who never did these things and presented as stereotypical boys as young children.
For transgender girls (Female to male), they may wear boys clothes, play rough and tumble games typical of boys (wrestling, etc), simulate war games, be comfortable playing with other boys, not want to wear dresses or play with dolls. Also, as with boys, there are many transgender adults who as young girls did not appear particularly gender a-typical.
Young children of course don’t have a vocabulary to describe who they are, but they might think in terms of “the same as”, as in “I am the same as Mommy”, or “I am the same as Daddy’.