But, surgery - not offered in New Zealand - could improve her chances of one day being able to walk up steps.
"It's a spinal operation and they go in and stimulate the nerves so they find the right nerves, and they cut the nerves from the spastic or tight muscles coming back into the spinal cord," her mother says.
Dr Park, in St Louis, offers the surgery.
Liv's surgery was scheduled for October but has been brought forward to May and her family are fundraising $120,000 to get them there.
"The reason I started looking into this surgery is about six months ago Liv said to me, 'Mum I really wish I could walk on crutches so I could go places with steps,' and it just really struck me because it's something we do all the time."
It's not Liv's first surgery, when she was four she had major surgery on her hips because they were underdeveloped and at risk of dislocating.
And she gets botox to improve the spasticity - but this surgery would mean no more botox, and is likely to help with hip development.
Her mother says the surgery is only the start of more hard work to come.
"Months and months of rehab, but if she works hard she will get the rewards, and it's been completely her decision."
Liv just competed in the Weet-Bix Kids tryathlon, as well as the Halberg Junior Disability Games.