Vain Queen returns to John Sadler's Caulfield stable this week to start her preparations aimed at a maiden Group One in the new year.

The talented mare scored an impressive win in a Group Three straight-track sprint during Melbourne Cup week at Flemington and will be given her chance in Group One company for the first time this campaign.

But which feature she resumes in is yet to be locked in.

"We're just working out whether she resumes in the Lightning or the Oakleigh Plate," Sadler said.

"Her main goal is the fillies and mares' Group One race in Adelaide."

The trainer said that now the mare had posted a Group win, earning valuable black type for her future breeding career, there was an opportunity to be a bit more ambitious.

Vain Queen has been in pre-training for two weeks after her spring spell.

"She'll probably come back (to Caulfield from pre-training) this week," Sadler said.

"She looks magnificent. She has really done well."

Vain Queen started her career with four straight wins and has now notched seven wins from 12 starts.

The five-year-old's explosive 3-1/2-length win in the G H Mumm Stakes (1100m) for mares on Oaks day was her fourth win from five attempts up the straight at Flemington.

Should the mare tackle the Lightning (1000m) it will be at weight-for-age against some of the country's top sprinters including Lankan Rupee, while the Oakleigh Plate (1100m) at Caulfield is a handicap.

Sadler said it was great to see Vain Queen win well in her final start of her spring campaign and is hoping she can raise her game again this time around.

"To take on those good sprinters she needs to go to another level, so it will just be interesting to see whether she can or not," Sadler said.

The trainer said the mare was likely to have a couple of starts in Melbourne before being freshened for the Group One Robert Sangster Stakes (1200m) on May 2 in Adelaide.