Like many aspiring beauty queens, Kum took part in the Miss Singapore Universe pageant last year for a shot at travelling overseas for the finals and to gain more confidence and poise.
But the beauty junkie also had another agenda: She had been working to launch her own mineral make-up brand with four business partners with a start-up capital of $80,000.
When she was crowned Miss Singapore Universe - she also won the Miss Body Beautiful and Miss Personality titles - she decided to test drive her products during the finals in the Bahamas.
"In the Bahamas, make-up had to stay on and look good the whole day because the contestants had to do a lot of photo shoots and we don't get a lot of sleep," she says.
Many of her fellow contestants experienced breakouts due to the gruelling schedule, she says, but her mineral foundation worked so well that many contestants asked her about the products she was using.
Her make-up line, Rachel K Mineral Cosmetics, had its soft launch in January and is currently sold at the two DermaSolutions spas here, where she works as the brand manager.
It is also available online at www.rachelkum.com. Prices start from $35 for a concealer and $55 for foundation.
"Winning the title gave me a headstart," says Kum, who also stars in the advertising material for the brand.
'The feedback from the contestants gave me confidence and I am going to send some products to them. Hopefully, they may endorse the brand in the future.
"Customers also find my products more credible when they know about my title, I guess, because my reputation is at stake if the products are not good."
She graduated with a degree in finance from the University of Western Australia, used to work as a commodities and futures analyst for a hedge fund and says that she has always been business-minded.
A early adopter of mineral make-up brands like bareMinerals, she worked with chemists and aesthetic doctors from the United States for her make-up line.
The Rachel K line, she says, offers preservative-free mineral cosmetics with shades suitable for Asian skin, unlike many American mineral make-up brands.
The lightweight formulation is also suitable for Singapore's humid climate and offers lightening and whitening properties.
The brand also offers a blemish balm that is made in South Korea and she would like to branch out into skincare products in the future.
Her ambition is understandable. After all, her pageant contacts have exposed her to a wide range of successful types.
For instance, a fellow Miss Universe contestant came to Singapore for last year's F1 festivities and introduced her to Richard Branson.
"He is very interesting," says Kum of the British business mogul. "And his achievements are very inspiring."
This article was first published in Urban, The Straits Times.