In the US more young people are defining themselves as transgender, raising questions over what is the appropriate age to undergo a sex change operation. Jeannette Francis filed this report for Dateline.
On the surface, Coy Mathis is a typical seven-year-old girl.
She likes dressing up, gravitates towards the colour pink, and enjoys playing with her dolls.
But Coy was born a boy.
For Coy's doting parent's Catherine and Jeremy Mathis, it's been an eye-opening journey.
"That's who she's always been," says Mrs Mathis.
"Really as soon as she could talk, she was showing us and telling us that she felt like a girl. It wasn't until she was closer to two-and-a-half and three that she was saying 'I don't want to be a girl, I am a girl'.
"She was trying so hard to tell us how she felt and we were ignoring her. And so she started sinking into a depression and started having anxiety about going anywhere where people would know that she was a boy."
Various medical professionals agreed Coy was transgender.
She was diagnosed with Gender Identity Disorder -- a condition characterised by overwhelming feelings of identification with the opposite sex, of being born into the wrong body.
Backed by medical experts, a growing number of parents in the United States are allowing their kids to live openly as the other gender.
The increasing number of young people undergoing gender reassignment has raised questions over whether children have enough opportunity to understand their identity before making the switch.
"We are seeing more, but because society is becoming more permissive and not pushing people into the closet or worse, into antisocial behaviour or chemical dependency or suicide," said leading transgender surgeon, Dr Marci Bowers.
"We do know still that 50 per cent of transgender youth attempt or commit suicide and so that's still a troubling statistic."
For the past year Coy has been living openly as a girl, and the difference in Coy's demeanor changed almost overnight, says Mrs Mathis. Coy became "thrilled with herself, and wanting everybody to see her and who she was."
However, a few challenges remain.
The Mathis family was recently at the centre of a media storm after Coy's school banned her from using the girl's restrooms. The family filed suit and Coy and her siblings are now homeschooled.
Debate also continues in Arizona over a controversial bill in the state of Arizona that would make it an offence for a transgender person to use the bathroom of their choice.
"The bottom line is that transgender people represent an extremely minute fraction of the population," said architect of the bill, Arizona state legislator John Kavanaugh.
"I'm not really sure if I want to make 90 per cent of the people really upset and concerned especially when children are involved to placate a minority."
Following public outcry the bill was amended, but it still allows private business owners to dictate the rules of private bathrooms.
Coy's mum says despite the challenges her daughter will face in the future, they "would rather have a child that is happy and a little bit different than what we imagined than have a child that's depressed and unhappy.
"Being transgender shouldn't be something to be ashamed of, you're just a little bit different and we just kind of need to get to that point in society that it's OK to be who you are, even if you're not the ideal."