Like Sunlight, In Secret won the top three-year-old sprint at Flemington during the spring, the Group 1 Coolmore Stud Stakes (1200m), and whereas Sunlight remained in Melbourne to start her autumn, In Secret has campaigned in Sydney.
In Secret resumed to claim the Group 2 Light Fingers Stakes (1200m) at Randwick first-up before running third in the Group 1 Surround Stakes (1400m) on February 25.
In the spring, In Secret went into the Coolmore fourth-up.
She ran second first-up, won the Group 2 Run To The Rose (1200m), finished second in the Group 1 Golden Rose (1400m) before claiming the Coolmore.
Cummings said the team has faith in in Secret to perform well on Saturday.
"We've got full faith in her ability to run right up to that performance she showed in the Coolmore against the colts," Cummings said.
"She's had the proper grounding, third-up into the Newmarket, and we are delighted with the way she's freshened up since the Surround when a gallant third in the inferior going on the inside.
"I think we can trust that form. They are top fillies and the three-year-olds have already been competing beautifully against the older horses."