Craig Williams rode She's Fit in Saturday's Group 1 Australasian Oaks (2000m) and was glowing in his assessment of the three-year-old after she ran a close second to Affaire A Suivre.

She's Fit settled towards the tail of the field for Williams and produced a strong finishing burst down the outside, but fell a neck short of snaring a third feature win.

Trained by Dan Morton, the daughter of Pride Of Dubai showcased her abilities by winning the Group 3 WA Oaks (2400m) and Listed Natasha Stakes (2200m) double at Ascot in March.

Before heading to Adelaide, she ran third to the John O'Shea-trained gelding Awesome Rock and stable mate Another Chino in the WA Derby (2400m).

Top Perth jockey Chris Parnham will partner She's Fit in the South Australian Derby with Williams to team up with Giga Kick in the Doomben 10000 (1200m) in Brisbane.

Williams believes Parnham will have an excellent opportunity of claiming his second Group 1 success in the South Australian Derby on May 13.

"I couldn't have higher praise for her, by performance and Dan's placement of her," Williams said on Tabradio.

"It's not even what she did in the race, it was probably what she feels like and what she is going to get to.

"She was really determined and really solid and any further she would have won.

"She's not just a three-year-old filly in my eyes, she's got a lot of scope and very good ability.

"She's still learning her craft, but she is going to be a filly to be reckoned with, especially as she stays quite well.

"I think Dan's chosen a really good race for her to go against the boys and I think they are going to have to beat her."

She's Fit currently heads Tabtouch betting at $4.80,  ahead of Loco and Promises Kept ($6.50).

Suizuro and Red Sun Sensation are next at $7.

Trainer Peter Moody's Run Sun Sensation, a winner of the G3 Chairman's Stakes (2000m), is owned by Perth trainer-breeder Sue Olive and her husband Alan.