Meet the transgender girls fighting for their right to stay female.

Emma Hayes is 12 years old. She likes makeup, and she’s starting to be interested in boys.

For any parent of a teenager, the approach of puberty is a daunting time. But for Emma’s parents, it’s taken on a whole new meaning.

That’s because Emma was born a boy — although “Ronan”, as she was then known, is now a figment of the past.

Speaking to 60 Minutes‘ Karl Stefanovic, Emma and her family reflected on how their family ended up here. When Emma was only four, her mother found her in her room with a knife attempting to cut off her own penis.

“She just didn’t want it there. Didn’t think it belonged there,” says her mother.

At age eight, Emma was diagnosed with Gender Dysphoria, and with the diagnosis came relief for her family. The Emma her parents know now is “totally different” to their tortured son.

“She can be who she wants to be,” her mother observes.

And, acknowledging the high suicide rates of Gender Dysphoric children, they're both hugely relieved with the way things have turned out.

"I couldn't see a future for Emma if we forced her to be Ronan," her father told 60 Minutes.

"I don't think she would be coping," agrees her mother.

"There are some times when you sit back and go, 'What would Ronan be like now?' Even though Emma's an awesome kid, I can't fault her... it's a weird feeling, I can't explain it."

Now, Emma has started high school. At first, some kids picked on her, saying things like "you're a boy". It made her feel sad, but her parents have decided the best policy is to ignore the bullying.

With her parents' support, Emma is about to start taking drugs that will stop her from hitting puberty. The drugs will stop her from growing into a man.

"What worries you about becoming a boy?" Stefanovic asks.

"They're smelly," Emma jokes. (Post continues after video.)

Fifteen-year-old Izzy has a story is much like Emma's. As a child, she wanted to dress like a girl: painting her nails, wearing tiaras. Her parents knew she was different from their older sons, but they didn't realise quite how different until she, too, was diagnosed with Gender Dysphoria.

Describing what it was like to live as a boy, Izzy says it felt like she was trapped in "a very small cage where I couldn't move around very much."

Now, Izzy has been on puberty blockers for five years. It's an enormous change for her, both physically and mentally. She describes the feeling as that of a "free bird."

But putting Izzy on puberty blockers wasn't an easy decision. One of the major side effects is that she'll never be able to have children of her own. Doctors offered to collect sperm from her before the puberty blockers took effect, but when Izzy heard that doing so would require her to go through the beginnings of male puberty, she vehemently declined.

"That was just not going to happen," Izzy's mum says.

Soon, Izzy will begin hormone replacement therapy, which will give her the opportunity to experience symptoms similar to female puberty.

It's an expensive process, and involves jumping through various legal hoops.

"I don't think it's the court's decision," Izzy's mum argues. "It's a medical decision. It should be dealt with by the appropriate medical people."

When asked about gender reassignment surgery, the parents of both girls are adamant it's on the cards. But when asked about whether it's something that should be allowed before children are 18, Emma's parents don't have a final answer.

"That's a hard question," Emma's mother acknowledges. "From Emma's perspective, yes. However, as a mum, that's where it's sort of like... she's 12. Yes, she knows what she wants, but surgery right now..."

Emma's parents have a plan already in place, however: "She's already hit me up. Eighteenth birthday, we're going to Bangkok for boobs. I said yep, I would take her."

A friendship between Izzy and Emma is quickly blossoming, borne out of their shared experience.

"Izzy understands, because we're the same," Emma says. "Other people just don't understand."

When asked if she has any advice for Emma, Izzy doesn't hesitate.

"I would tell her to keep fighting for who you want to be. She should show her opinions and feelings, and no-one should stop her for that."

Featured image: 60 Minutes/Channel Nine (screengrab)