Promising mare She's Ideel will be on trial for a Sydney Cup campaign when she takes on a seasoned field of stayers in the St Leger at Randwick.

The five-year-old has had a luckless preparation and again looked like she would emerge with a tale of woe last Saturday when she was flushed out before the corner and impeded for clear running.

But once balanced up, She's Ideel lifted herself off the canvas and finished hard to score a narrow win.

Trainer Bjorn Baker has given her an easy week and the mare will take her place in Saturday's St Leger Stakes (2600m) at Randwick in what will be an important test.

"Her win last week was remarkable with the interference she got at about the 700 all the way to the 400. I thought it was a really big win under the circumstances," Baker said.

"She looks to have come through well, she gets in with no weight, Rachel King is on.

"She has only had one run over the 2400 and she won that day. I think 2600 will really suit her."

She's Ideel faces a tough field of proven performers including the Chris Waller-trained pair of Brimham Rocks and Wu Gok, along with Wyong Cup winner Paths Of Glory, who is back in grade after a last-start fifth in the Group One Metropolitan Handicap.

If the lightly-raced mare can prove her credentials at Randwick, Baker confirmed it would open the door to a Sydney Cup campaign.

"That would be the first plan of attack, to look at a race like the Sydney Cup in the autumn," he said.

Stablemate Fun Fact will also contest the St Leger after returning from a trip to Brisbane where Baker said he was "a tad disappointing" in finishing fourth to Grey Lion.

"On his day he is a good horse. It was only in the autumn he ran second to Mugatoo in the Canberra Cup so he's got some reasonable form lines, but he is going to have to put his best foot forward," Baker said.