She also kicked three conversions to score 21 points when Otago Girls' was beaten 36-0.
The other standout players were Lily Cotter, who scored two tries, Libby Jones, who used her strength to score a try, flanker Bridget Hendry, who won ball at No 2 in the lineout, and lively flanker Hannah Perkins.
The St Hilda's team, coached by Mark Scully and Warren Alcock, showed more structure and used its backline efficiently.
Otago Girls had a rugged pack but it did not co-ordinate its attack. Hooker Eilish Thomson and No 8 Hannah Todd ran aggressively with the ball in hand but the backline did not function on attack.
The tackling was strong and some big hits were made by both teams.
St Hilda's, the runner-up to Taieri College last year, will play the winner of the Southland competition.
St Hildas 36 (Libby Jones, Lily Cotter 2, Olivia Waldron 3 tries; Waldron 3 con), Otago Girls' 0.
Halftime: St Hilda's 17-0.
