Former Featherston School principal David Winter remembered her as a bright and bubbly girl who always had a big smile.
"She was a girl who found life exciting and amusing."
He said she had lots of friends and was a good student who applied herself to her schoolwork.
Deputy principal at Kuranui at the time, Geoff Shepherd, said it was a tragic accident and the community felt very sad for the family.
Grandparents Dick and Kiri Smith live in Featherston.
Mrs Smith was too distraught to talk to the Wairarapa Times-Age.
Ms Smith leaves behind her much-loved 7-year-old son Kingston.
Her brother Anton Smith-Waaka told Radio NZ he and his brother Spike were very close to their older sister, particularly after their mother died just one and a half years ago.
"She was a really great, caring person and she [was] fully devoted to her son.
"Most of her attention and love and devotion just went to her son, that was all she pretty much worked around."
Party guest and friend Shan Owen said Ms Smith's partner had driven them up to Northland for the weekend.
"He's devastated ... but he's handling it pretty well.
"But it's even worse for that 7-year-old boy, he's lost his mother."
He said it was the first time she had been away from her son for any length of time.
Harmony Smith took to Facebook and posted that she was shattered by her cousin's death.
"Gone too soon my beautiful cousin. Why now, why you? Words can nowhere near describe how I'm feeling," she said.
"I stayed up all night praying you'd come home to us."
Northland police spokeswoman Sarah Kennett said that about 6am Ms Smith went to check on her car, which was partially submerged by rising flood waters, when she got caught in the current.
Mr Owen said he saw her lose her footing.
"She went for about 20 metres and got caught in a fence.
"Then she got swept under and no one saw her again."
Mr Owen said she was trapped against the fence, screaming.
"She screamed solid for five minutes. Then her legs went up in the air and that was it, that was the last I saw her."
Three others tried to rescue her but were swept away, one clinging to a tree for three hours.
Search and rescue staff saved them but could not find Ms Smith.
She was found on Sunday when river levels downstream from the Haruru Falls had dropped.
- APNZ, additional reporting APN News & Media