[1] Hillier was born in Geraldton, Western Australia and plays at Lincoln Golf Club, Torksey.

She was a 2012 member of Golf Australia's National Squad, and finished 3rd at the 2012 Espirito Santo Trophy Amateur Team Championships together with Brianna Elliott and Minjee Lee.

In her rookie season, she played in 15 tournaments and recorded a best finish of 3rd at the Allianz Ladies Slovak Open.

In 2017, she finished 3rd at the Ladies European Thailand Championship, two strokes behind winner Atthaya Thitikul, and in 2018 she was 4th at the Hero Women's Indian Open.

[2] The following week, she lost a playoff to Tiia Koivisto at the Jabra Ladies Open held at the Evian Resort Golf Club in France, after shooting her fifth career hole-in-one in the second round.