On the eve of this year's Golden Slipper in Sydney, the 2017 winner She Will Reign will be in Melbourne bidding to snare the third Group One victory of her career.

She Will Reign is already a Group One winner of the Moir Stakes at Moonee Valley last spring and returns to the Melbourne track primed for Friday night's William Reid Stakes (1200m).

"She's ready to win," trainer Gary Portelli said.

"She had a gallop between races at Warwick Farm last week and she had a good gallop on Monday morning as well.

"She looks absolutely sensational. So we're in a good place."

She Will Reign won the Inglis Sprint in Sydney in the first start of her current campaign before finishing midfield in the Group One Oakleigh Plate at Caulfield last start on February 24.

The filly has drawn the inside barrier in a field of 10 for the weight-for-age William Reid, although four of the acceptors - Supido, Secret Agenda, Thornum, Pariah - have also been paid up for The Galaxy in Sydney on Saturday.

Moonee Valley has been the scene of two Group One wins for Portelli, with She Will Reign powering home out wide in this season's Moir while former stable star Rebel Dane won the 2016 Manikato Stakes.

But another of Rebel Dane's Moonee Valley runs - his close fourth in the 2014 Manikato Stakes - has sprung to the Sydney trainer's mind after Wednesday's draw.

Portelli hopes She Will Reign, who will be ridden by her Golden Slipper-winning jockey Ben Melham, will not strike any traffic issues from her inside barrier.

"I'd rather barrier one than ten," Portelli said.

"But I've still got this memory of Rebel Dane getting held up on the fence in the Manikato that year and he couldn't get out.

"But I'd never knock back barrier one.

"From the 600 metres onwards at the Valley you've got to get on the back of the right horses. You've got to get into the race. You've got to get through at the right time.

"I haven't had a chance look at the speed map yet but from barrier one I'd like to see Benny use her a little bit, to be in the right spot when he needs to be."

She Will Reign was the $5 favourite in early betting on Wednesday in an open market with Pariah at $6 and Group One-winning mare Secret Agenda at $7.