"It created a bit of stress for her parents," her aunt, Gail Savage-Highnam, said. "But she was proud to represent New Zealand today."
Smith is keen to one day win Olympic gold and won her first world title in front of her mentor and Olympic silver medallist Sarah Walker, who will be chasing her second world crown when the elite racing is held this weekend.
Smith was second at the world championships in 2009 and 2010 so yesterday's win was special. She was fourth in her first moto but won her last five races, including the final when she dominated from the outset.
"I'm working towards getting to the Olympics and I'm pretty sure I can do it," she said.
"I have the talent to do it and everybody says I am good enough so it's just a matter of making it happen.
"I have learned a lot off Sarah and she has been my biggest fan. I'm improving so much just by talking to her."
Smith will step up in age group today when she races in the girls' under-16 cruiser class and her brother Lewis (14 years) and sister Taylor (16 years) begin their competition.
Three-time world champion Rico Bearman of Albany, racing in the 10-years class, looked on course for his fourth world title after winning all of his early races but finished fifth in his semifinal to miss out on a place in the final.