Jason Warren and his assistant trainer Mitchell Beer cheered Shamus Award home in the Cox Plate like he was a member of their own stable.

He isn't, but Warren prepares the Danny O'Brien-trained colt's older half-sister Double Dee who heads to Moonee Valley on Saturday aiming to continue an already lucrative few weeks.

Warren has always had a high opinion of Double Dee and two provincial wins since her younger sibling's Cox Plate heroics have reinforced his belief in the mare.

Shamus Award's success has already boosted Double Dee's potential broodmare value, and she will attempt to add to it with a city win on Saturday and then a black-type mission next winter in Queensland where she is likely to strike wet tracks.

"All week leading into the Cox Plate Jason and I were talking about how great it would be even if Shamus Award could run in the first four just to help her along," Beer said.

"We watched the race together and we were just shocked after the race.

"We cheered Shamus Award home like we owned him ourselves."

Beer joked Double Dee, a $32,000 yearling purchase, must have read the papers after the Cox Plate and thought she better pick up her game, which she has.

"Ever since he's saluted she has raised her game," Beer said.

"I guess you could say at some stage there it was looking like she wasn't going to measure up to what we thought of her, but she's found a leg this preparation and who knows how far she can get."

Double Dee is entered for two races at Moonee Valley over 1600m with a decision which race she contests to be made later in the week.

Stablemate Proper Madam is a chance to clash with Double Dee but could also be saved for a race at Bendigo next week.

Four-year-old Double Dee, who has won three of her 13 races, stepped up to 1600m for the first time last start and won by eight lengths in slow going at Ballarat.

Beer said the mare had come through that race in great order.

"She was bouncing this morning so we can't fault her coming through her run at Ballarat. We'll be heading to the races on Saturday thinking that she can really do the job."