Heather, 45, who lost part of her left leg in a motorcycle accident in 1993, seemed thrilled with her win as she said: "Thanks New Zealand for a great race, you did a great job. Thank you," upon collecting her medal.
The former model is ranked number 28 in the world but won the silver medal after recording a time of 2 minutes 9.09 seconds at Coronet Peak in Queenstown.
The top prize went to Melanie Schwartz of Canada who recorded a time of 1.59.79.
In 2012, the star exclusively spoke to HELLO! Magazine about her pride at being chosen to race for the British Disabled Ski Team and her dreams of competing at the London Olympics.
She has also spoken of her desire to become a member of the British Paralympic Team at Sochi 2014.
"My goal is to get to Russia and to win a medal," she declared to HELLO!.
Heather bought a a £1.4million ski chalet in the Austrian Alps in 2011 in order to prepare for the 2014 Winter Paralympics, and it seems her hard work is paying off.
A source told The Mirror at the time: "The apartment is right in the centre of a ski-lovers' paradise. Heather loves skiing and this will be a brilliant place for her to train for the Paralympics.
"She's also looking forward to spending some nice holidays there with her family and friends. Heather fell in love with the eight-bedroom holiday chalet when she stayed there last year.
Heather's chalet is located in the vicinity of 24 ski resorts. One of the nearby resorts is Goldek am Millstatter, which has the longest black run in the Alps.
The mother-of-one married Beatles star Sir Paul McCartney in 2002 but they separated four years later and in 2008 they finally divorced after a protracted battle through the courts.