"We're focused on achieving small milestones. The first is, we got her to preschool. The next is for her to learn how to read. She just loves learning,'' Mrs Potts said.

It's far beyond what doctors told Mrs Potts and her husband Adam 18 months ago when Annabelle was diagnosed with a highly aggressive and difficult to treat brain tumour within her brainstem.

"They said, 'There's no treatment. Even with radiation, she has six to nine months to live. Go home and make memories','' Mrs Potts said.

Now defying those dire predictions and 18 months post-diagnosis, Annabelle is being kept alive, her parents believe, through treatment she is receiving at a clinic in Mexico and the generosity of the Canberra community.

In Mexico, Annabelle is receiving a combination of intra- arterial chemotherapy and immunotherapy, treatment, which, until recently, appeared to have stopped the growth of the tumour.

Annabelle was on three-monthly visits to Mexico, with scans as late as February showing her tumour was "inactive'' and had not grown. Mrs Potts said since then, there had been "a tiny bit of growth'' in the tumour, but not in the brain stem, some cause for optimism because anything in the brain stem was inoperable.

Annabelle, who turns five on June 10, must now make six-weekly trips to Mexico, each excursion costing $30,000 in treatment, accommodation and travel.

Mrs Potts said the she believed the Mexican clinic was different to Australian treatment because it worked to get chemotherapy drugs as close to the tumour as possible, by inserting a catheter in the groin and releasing the drugs.

Federal Health Minister Greg Hunt, in a letter to Mrs Potts, has sided with the Australian medical community in maintaining the treatment in Mexico is experimental and has not presented any data to demonstrate its efficacy.

Mrs Potts believes Australia needs to at least trial the Mexican treatment.

"Children are her stage can't walk, they're in wheelchairs, they have feeding tubes,'' she said.

"We need to get this treatment in Australia, because going to Mexico is not maintainable.''

Mr Hunt said the advice put to him was that any stabilisation or improvement in Annabelle's health was due to radiation she received in Australia.

Mrs Potts disagreed, saying Annabelle's own doctors in Australia had been impressed by her progress, even though they could not endorse the Mexican treatment.

"As Annabelle’s parent – spending every moment with her and scrutinising all of her symptoms – I am convinced that the Mexican treatment is responsible for Annabelle’s improvement,'' Mrs Potts wrote in a letter to the minister.

"Not only do the improvements in MRI results coincide with the Mexican treatment, her physical symptoms improved after only one treatment.''

Mrs Potts said the only way her family could continue the treatment in Mexico was through the generosity of the Canberra community. She was devastated by the response of the Australian Government which has not provided any funding.

"We shouldn't have to be pushing so hard, fighting so hard,'' she said.

"If they don't want to support us financially, give us some treatment options. Saying there is nothing we can do is not an option for me.''

Mrs Potts is a public servant, and Mr Potts, a carpenter. They recently welcomed their third child Juliette, almost three months ago and also have a son William, who is two.

"We are just so grateful to the Canberra community because we could not do this without them,'' she said.

Annabelle's teacher at Miles Franklin preschool in Evatt, Lalangi Abhayapala, is just one example of how Canberra is continuing to back the family.

Mrs Abhayapala is shaving off her long hair on Saturday to help raise funds for Annabelle's treatment.

"I met Annabelle at the end of last year and heard her story and became very emotional,'' she said.

"And as a teacher, I can't be emotional, I have to be strong. So I started to think about what I could do.''

Mrs Abhayapala said she regularly spent $400 on treatments to straighten her hair and thought that money could be put to better use. She then enlised the help of the preschool which is holding a celebration around the shaving from noon to 2pm on Saturday.

"The school community, it's amazing,'' Mrs Abhayapala said. "And I knew if I did something, the community would be behind me.''

To make a donation to Mrs Abhayapala's fundraising, go to https://www.mycause.com.au/page/177345/to-help-annabelle-potts-fight-dipg

A fundraising Love for Annabelle dinner has also been organised by Mrs Potts' school friends, at the Southern Cross Club in Woden on Saturday, June 30. Tickets are available at https://www.eventbrite.com.au/e/love-for-annabelle-fundraising-dinner-tickets-41739457842?aff=eac2

The Potts, meanwhile, are refusing to give up on their child.

"She loves arts and craft. She loves to jump on the trampoline, she always did, but I never thought I'd see her do that again. I walk with her to preschool and I love to see her run ahead because she can't wait to get there,'' Mrs Potts said.