The drug transformed her from a state of constant sedation to a bubbly, responsive child.
Mum Karen Jeffries said she knew the drug worked, given her daughter's improvement since she started taking it in 2015.
"She's just built up a bit of an immunity to it in the last few weeks which means she's not doing so well. She hasn't been coping well at school so has had the last two weeks off. The seizures are a bit stronger, and because the school doesn't have nurses equipped to deal with that, it's better to keep her at home.
"Term 4 last year she had an amazing time, she didn't have a single sick day. I never thought it could be like that. We were thinking 'so this is what normal life is like'. The medication has done a huge amount for Zoe.
"The last few weeks have made us realise how good we had it and there's the potential for it to be that good again, which is why we're looking for alternative options."
Mrs Jeffries said they had enough in a trust, made up of donations, to continue buying Sativex for the next 12 months, but there was always the concern the money would run out.
"As a family there is no way we could pay $1000 a month for the drug, so the generosity of the community has been mindblowing. It's also been overwhelming because we feel like we can't return the generosity.
"We are so incredibly grateful, I cannot stress that enough."
Some of the alternative options for Sativex were a bit cheaper, Mrs Jeffries said.
"Even if it's $700 a month, that's $300 spare that will give her more time in the long run."
To help the family out, Fernleaf Motel owners Andrew and Wendy Bell are holding a fundraiser over winter.
For $5, locals can take a dip in the motel's heated outdoor pool or indoor mineral pool, with all proceeds going towards funding Zoe's medication.
Mr Bell said he had met the Jeffries family through Medical Cannabis Awareness New Zealand, and wanted to help out.
"There are so many hurdles to get access to cannabis-based medications and I know how helpful it is so if we can help pay the $1000-a-month bill so that Zoe can take it, we're happy to help.
"We figured our pools are there, why not use them as the fundraiser. We'll run the fundraiser all through winter and see how it goes.
"I also hope that through this it will get more people asking questions and getting the right information about medicinal cannabis products."
To donate go to givealittle.co.nz/cause/medsforzoe. For more information about the Fernleaf Motel fundraiser, call (07) 348 7129.
