For years, they were told nothing was wrong with their daughter.
Grace – or Poss as she is known – slept for only a few hours a night, refused to eat, struggled to follow instructions and took everything literally.
When a friend jokingly said "what are you going to do, hit me?", Poss responded with exactly that, striking her in the face. And when she was asked to hop to the dinner table, she bounded through the house on one foot.
Her parents Renee and Aaron Bugg raised their concerns with staff at Grace's daycare centre.
"They said girls are fine," Renee said.
They tried to get a diagnosis at a public hospital and were told there was up to a five year wait.
But when Poss started prep, they sought an opinion from a private paediatric practice and received an answer that finally made sense – autism.
A recent online survey of almost 2000 families with autistic girls paints the picture of a condition that is often poorly diagnosed in females, and 51 per cent miss out on early intervention.
Boys are four times more likely to be diagnosed with autism than girls, and there are concerns that diagnostic tools are geared towards males.
Clinicians say girls are often better at masking autism by imitating verbal and social skills, have less repetitive behaviour and are less likely to be fixated on niche topics of interest.
The survey, which was conducted by advocacy group Yellow Ladybugs and sent to the United Nations Office of the High Commissioner for Human Rights for a report on the rights of the child, also highlighted high levels of sexual and physical assault among autistic girls.
And almost one in five parents said they were unable to access education for their daughter, due to suspension, exclusion or being sent home. Thirty-nine per cent said they had moved schools because their daughter's needs were not met.
Poss was among them and changed schools at the end of grade 3 after spending a year sitting outside her classroom. Her teacher refused to acknowledge her diagnosis and sent her there because she was being "disruptive".
"She said 'I have worked in boys schools for years I know what autism is and this is not it'," Renee said. Poss also became suicidal.
The 11-year-old is happier now, but there are still challenges.
Just the other day the academically gifted child received instructions for a simple task in the wrong order.
Her mum asked her to put her shoes and socks on, and Poss tried in vain to put her socks over her sneakers.
Yellow Ladybugs founder Katie Koullas said that many girls were not diagnosed with autism until their early teens, and some had to wait until adulthood.
"We hear from women who say if only I had known earlier so I could accept myself and work to my strengths," she said.
The group was founded last year and creates social events similar to birthday parties for females with autism, while also supporting parents.
Professor Cheryl Dissanayake, director of the Olga Tennison Autism Research Centre at La Trobe University, said it was too early to say definitively that autism manifested itself differently in girls.
"There is not strong enough data," she said. "We have looked at these early autism symptoms in very young children, and while boys tended to have slightly more repetitive behaviours, by and large we found no differences in autism symptoms or cognition."
But she said many clinicians reported that girls present differently to boys.