In 2010, Lee became the youngest winner of the WA Amateur Open while still a year 9 student at Methodist Ladies' College, Perth.

[1] At the start of 2012, she was moved from MLC to Corpus Christi College, to be closer to Royal Fremantle Golf Club.

[7] Lee became the number one ranked amateur golfer on 26 February 2014 after winning the Oates Victorian Open on the ALPG Tour.

[8] She remained the number one ranked amateur golfer until she turned professional in September 2014 after leading the Australia team that won the Espirito Santo Trophy.

[10] Lee represented Australia in the women's golf competition at the 2016 Summer Olympics in Rio de Janeiro, Brazil, finishing in a tie for 7th.

[12] She also became the first woman to win the Greg Norman Medal for being the best Australian professional golfer on the world stage.

[10] By late the following month, she had risen to number two in the Women's World Golf Rankings, but in her home country she still had such a low profile that she was described by The Age as the "Invisible Champion of Australia".

She was ranked fifth in the world before her win, just behind fourth-ranked Atthaya Thitikul[15] who finished the final round with a 63, good for a tie for eighth place at 13-under-par.