Campbelltown's Myla Taylor experienced her first seizure at just seven weeks old.
Several weeks later she was diagnosed with a rare and lifelong form of childhood-onset epilepsy, Dravet Syndrome.
Dravet Syndrome only affects one in 20,000 people worldwide and it is difficult to treat with conventional epilepsy medication.
Myla's father, Dean, said this made the diagnosis even more difficult.
"Her seizures would last for up to four hours at a time - which was very scary for us as parents," he said.
"Everything that we had read told us that the syndrome would be very difficult to treat with the conventional epilepsy drugs.
"She hit every milestone in her first year, but after that she slowed down and she is now developmentally delayed which is common with Dravet Syndrome.
"We tried about 10 anti-epileptic drugs before she was given access to medicinal cannabis."
Myla, now seven years old, was eligible for a NSW Government program which allowed her family to access Epidyolex, the first and only cannabis-based treatment for seizures associated with Dravet Syndrome in patients aged two years and older.
Mr Taylor said Myla's life, as well as her family's lives, improved with use of the new medication.
"She responded quite well - the length of her seizures reduced significantly," he said.
"When she was having four-hour seizures we would have to call the ambulance and pile the other kids into the car to head to the hospital.
"Her seizures now are around one to two minutes in length and we haven't had to visit the hospital in two years.
"Myla is able to spend more time being a kid again, which has been life-changing for our whole family.
"We're no longer on edge all the time, and don't feel like we might need to drop everything at any minute."
Epidyolex became available on the Pharmaceutical Benefits Scheme (PBS) on May 1.
Mr Taylor said he had hope for future generations affected by Dravet Syndrome now that the drug was more readily available.
"We used to have to drive into the children's hospital to go and pick it up, and for people not in the program it would cost them tens of thousands of dollars," he said.
"Now that it is on the PBS when get get it from our local chemist with a prescription."
Mr Taylor encouraged parents of children with Dravet Syndrome, or epilepsy in general, to talk about it.
"I am a big advocate for talking about it and finding that support," he said.
"There are groups out there and Facebook groups, where you can reach out and talk to others who are experiencing the same thing."