She is the sister of Maxine Blomquist and a cousin of Shirley Langrope, who are also former New Zealand netball internationals.

On 2 February 1985, she made her senior debut against England during the netball tournament at the Australia Games.

[1][2][9] She was subsequently a member of the New Zealand team that won the gold medal at the 1985 World Games.

[10] A knee injury on the eve of the 1987 World Netball Championships limited Heffernan's involvement to just one match.

[15] At the 1990 Commonwealth Games, she also played for New Zealand against Australia in a one-off match when netball was a demonstration sport.