The relaxed nature of Peron has allayed the fears of jockey Michael Cahill about her ability to cope with a seven-day back-up in the Tattersall's Tiara.

Cahill has ridden Peron in trackwork since her impressive win in last Saturday's Gai Waterhouse Classic (1350m) at Ipswich and is impressed with her appearance and mindset.

"I've been on her a couple of times this week and she's very bright," Cahill said.

"She doesn't appear to have taken any harm from the run. Physically she's as good as she could possibly be."

Peron is one of the favourites for the $500,000 feature at Eagle Farm on Saturday, the final Group One race of the Australian turf season.

Cahill believes the filly's composed nature is typical of horses trained by John Thompson.

"John's specialty is keeping them calm and relaxed and this filly is a perfect example of that," he said.

"She's never had pressure put on her at any stage."

Peron was forced to race three wide at Ipswich and impressed Cahill with how quickly she recovered from a bump on the home turn.

"Some horses would've turned it up but she didn't," he said.

"It took her a stride or two to get balanced again but once she gathered herself up she really found the line strongly."

The Ipswich track was rated slow when Peron won the Waterhouse with a similar rating expected in the Tiara.

Cahill is adamant the filly isn't as well suited when the tracks are rain affected.

"Ipswich wasn't her preferred ground and the fact she was still able to win was a great sign," he said.

"On top of the ground she's got a much better turn of foot. She can accelerate in a stride which is her real weapon."

Peron has firmed to $6.50 in the Tiara despite the wet track concerns.

Thompson is aiming for his first Group One win as a commercial trainer since the sell-off of part of owner Nathan Tinkler's racing team.

He won last year's Tiara with Pear Tart for Tinkler's Patinack Farm but rates Peron a superior filly.