Walker was clad in a tastefully clashing blue and yellow Mossman dress, with a blue fascinator designed by Claire Hahn.
The gravity-defying headpiece was reminiscent of a strand of DNA.
Both winners took home swag including vouchers for beauty treatments, a massive bouquet of flowers and a magnum of champagne.
Walker had spent the day with a group of friends and said she planned to share her champagne with them.
She had never entered a fashion competition before today, when she was picked with Mohammad and five others as a finalist.
"It makes me want to enter more," she said, joking that she might be back for the Boxing Day races.
The Christmas-time competition is serious stuff, with contestants shelling out hundreds or even thousands of dollars on their attire.
Walker was a stylist, so perhaps her win was no surprise.
"It's my job to look good - and make others look good."
