She looks like any other girl who loves dress-ups and painting her nails.

But 12-year-old Emma Hayes started her life as a boy named Ronan.

And the young transgender schoolgirl is set to undergo a life-changing hormone blocking treatment to become a woman.

The transition comes after her mother Meagan found her then-son attempting to cut off his penis with a knife at the tender age of four.

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Australian schoolgirl Emma Hayes, 12, (right) started her life as a boy named Ronan (left)

'I found her in the room just with a knife and pants down, and she tried to cut off her own penis,' Mrs Hayes told Karl Stefanovic on 60 Minutes.

'[She] wanted to cut it off. She just didn't want it there. She didn't think it belonged there. She only ended up with a little scratch.'

The Australian schoolgirl was diagnosed at the age of eight with gender dysphoria - a condition where people don't identify with their biological sex.

Emma, who now identifies as a girl, believed she was born in the wrong body - and at a very young age, she decided to make the transition from male to female.

She will begin taking a 'puberty blocker' - a drug to stop her natural hormone progression - and prevent her going through puberty as a boy.

Her parents Meagan and David have shown their support on their daughter's transition

Emma opened up on her transition from male to female with Channel 9's Karl Stefanovic

And her parents have shown their support by letting their daughter enrol in school as a girl and taking her shopping for make-up and clothes as she adapted to her new identity.

'I think we did [make the right decision]. I couldn't see a future for Emma if we had of forced her to be Ronan, I don't think she would be here,' her father David said.

For her 18th birthday, Emma has already told her mother that she wants to go on a trip to Bangkok so she could get breast implants.