Graff's little sister Steel Diamond will make her belated debut at Warwick Farm and according to trainer Rick Worthington, she has inherited her share of the family's ability.

The youngster will line up in the Darley Lonhro Plate (1100m), albeit a couple of weeks later than planned due to a minor setback.

The delay has meant Steel Diamond has to take on the colts and geldings, headed by unbeaten juvenile Time To Reign, but Worthington doesn't believe she will be out of her depth.

"She's up against colts and horses that have raced so she's got a mountain in front of her, I'm aware of that, but it's a starting point," Worthington said.

"Having said that, if they're going to hold their hand up as a potential possibility to get into the Slipper field you can't run and hide."

Worthington had to push the budget to $320,000 to secure Steel Diamond as a yearling, an investment that has since been boosted by the emergence of her full brother Graff as one of the best three-year-old sprinters in Sydney.

And Graff isn't the only family member making waves on the racetrack.

The Gai Waterhouse and Adrian Bott-trained Dawn Passage, favourite for Saturday's $2 million Inglis Millennium, comes from the same bloodlines being a half-sister to Dinkum Diamond, the dam of Steel Diamond and Graff.

Worthington is confident Steel Diamond has the raw ability to make a mark of her own and he won't be surprised if she shows that on Saturday.

"Pretty much once she was broken in, we were getting a little bit excited about her," he said.

"I wouldn't be surprised with anything she does because I know she is extremely talented and her ability is untapped."

Worthington's Golden Slipper aspirations for the filly will be given a useful litmus test at Warwick Farm against odds-on favourite Time To Reign who is also prominent in Slipper betting.