Born in the Auckland suburb of Māngere East in 2001, Neiufi is the eldest child of Tongan New Zealanders Lose and Fineasi Neiufi. She has six younger siblings.[1][2] At age two, Neiufi was run over in a hit-and-run accident and suffered damage to the right side of her head. She suffered bruising on the brain, hypertonia and has a left-sided hemiplegia and as a result the left side of her brain is smaller than the right, causing slower processing at times.[3] The left side of her body is also smaller and weaker than the right. After the accident, Neiufi had to be taught how to sit, walk and use her arms again.
As a child, she wanted to play netball but had difficulty keeping up with the other players. Her physiotherapist suggested she try swimming, and she started swimming at about nine years of age and competing the following year.[3][4]
In 2017 Neiufi won the Pacific Health and Wellbeing Award at the SunPix Pacific Peoples Awards in Auckland, New Zealand. She also received the 2017 Tongan Youth Excellence Award in the Senior Athlete category from the To’utupu Tonga Youth Trust.[3][9]