A mother who lives in Brisbane, Australia, has shared a heartfelt video on Facebook about the journey of her 9-year-old son, Milla, who was born as a female.

Renée Fabish, originally from New Zealand, posted the raw slide-show style video calling for support from loved ones as her child transitions. This personal message has now been viewed more than 3.5 million times.

"Hello my friends and family," Renée wrote. "I'd love you to watch this slideshow I put together. It explains some major changes that are underway for Milla and our family. Milla needs our support now more than ever!"

Milla has been diagnosed with gender dysphoria — a person identifying with the opposite gender to their biological gender — and explains in the heartbreaking video why "it is not easy being me." Milla has had to put up with daily bullying at school and has now announced from this day forward, "she" wants to be known as "he."

"I am having a really hard time at school at the moment. Kids tease me all of the time, they call me shim, gay girl and weirdo," Milla said. "People just don't understand me, nobody wants to be my friend ... I have decided I want to take the next step, from today I want to live and be known as a boy. I hope I have your support."

Using white text on a black background, Renée tells the emotional journey the family had gone on to come to this point, and the realisation that this is not a "phase."

"From as young as two Milla would refer to herself as girl-boy — a girl that liked boy things from very early on," Renée explains. "Milla insisted on wearing boys, undies, PJs and dress ups — we didn't have a problem with that.

"Everyone told us it was just a phase. They'd say 'she's just a tomboy — she'll grow out of it'."

"Her gender assigned at birth does not align with how she feels inside — Milla was born female but her brain identifies as male," Renee said. “It is not something she was talked into and it is not something she can be talked out of. It is what it is.”

“We have no doubt in our minds that Milla is fully invested in her plight to be recognised as a boy — the only thing that has changed for us is pronouns — we support him wholeheartedly.”

Gender dysphoria is when the person rejects the identity and gender they were born with, “causing clinically significant distress or impairment in social functioning or other important areas of functioning," the Medical Journal of Australia said in a report.

The mental and physical outcomes for transgender people are improved when gender dysphoria is treated at the optimal time in early puberty, the Royal Children's Hospital Melbourne said on its website. The initial treatment is medication to suspend puberty and is fully reversible, before moving to hormone treatments which require a court order and finally to irreversible surgery interventions in adulthood.

It is not known what the next step is for Milla, but the acceptance of his parents is a step in the right direction. “All we can do is equip our son with the skills necessary to cope with small minded people,” Renée added.