The Northland District Health Board (DHB) is funding the medication for Alisha for as long as it remained effective and was needed.
Mrs Butt said the couple wanted the drug funded for everyone who needed it and had organised a petition urging the Government to do so. Mr Butt said the Government was persecuting the vulnerable by failing to fund Sativex.
Mrs Butt said their daughter had a better quality of life due to Sativex. She could sleep for up to six or seven hours a night, whereas she used to wake every five or 10 minutes.
Mr Butt said Alisha's teacher found she was more cooperative and could cope better in school. Alisha was in her final year at Kaitaia College, attending special classes.
A Carterton family turned to the public to help fund the drug after teen Grace Yeats became the first New Zealander to be diagnosed with an incurable variant of acute disseminated encephalomyelitis.
Her mother Tracy Yeats said Sativex had been "life-changing" for Grace. She was in a great deal of pain and having a lot of dystonic spasms before she started using it. Now she was calmer, using her hands more and was overcoming her spasms. Late in February she started talking again.
Mrs Yeats the drug wasn't something she could afford without public help.
One Dollar Warriors - a group which raises funds to fight life threatening illnesses - set up a Givealittle fund for the Yeats family and collected enough to pay for Grace's Sativex for two years.
Rotorua girl Zoe Jeffries has uncontrolled epilepsy, spastic quadriplegia cerebral palsy, microcephaly, cerebral visual impairment and has had severe seizures since birth.
The Ministry of Health last year approved an application for Zoe to use Sativex.
Mother Karen Jeffries said the cost of the product was a huge burden but a Givealittle campaign to fund it had been "amazing".
In addition to its cost, reluctance among health professionals to talk about medicinal cannabis could also be a barrier to it use, she said.
Her family had done their own research around the drug and there was a long road to getting access to it, she said.
The Ministry of Health has received 76 applications for pharmaceutical grade cannabis products with consent for distribution in New Zealand over the past three years.
Sativex is approved for treating symptoms of multiple sclerosis in New Zealand. Any other use of Sativex is an "unapproved" use, according to Medsafe.
The ministry approved 73 of the applications, including 16 applications for renewal of previously granted approvals.
It received three applications for non-pharmaceutical grade products and authorised two.
The ministry has received no applications for products without consent for distribution in New Zealand in the past three years.