The Raise The Flag filly begins stepping up in distance today when she takes on the rating 65 fillies and mares over 1335m.
Wingatui trainer Terry Kennedy said the progression from 1200m at Wingatui on Boxing Day to today's extra 135m was part of the plan towards the 2400m classic at Trentham in March.
The next step would be at Wingatui on January 31.
''If she could win down there [Gore], I'd probably run her in a mile here - not the Guineas [over 1400m],'' Kennedy said.
''It would be a step up over a bit more ground and then we'll get her over a mile and a-quarter. If she gets a mile and a-quarter, hopefully she'd get the Oaks distance.''
Princess Brook followed up a win at Wingatui in October with a sixth in the 3yr-old 1200m at Wingatui on Boxing Day.
Kennedy was happy enough with the filly's Boxing Day run considering the distance is well short of her potential best.
''She's not a sprinter - she's more of a stayer,'' he said.
''She got run off her feet and made a bit of ground so it was a good-enough run, I thought.''
The $12,000 stake was the main attraction for Kennedy and owner Fred King while the barrier draw of 4 will certainly help.
''Gore's probably not going to be the best track for her because she's quite a big filly but it's a bonus race so she sort of had to go there.''
Leading South Island jockey Chris Johnson has the ride on Princess Brook and five of Kennedy's six other runners.
''The rider helps a lot. You're four lengths in front for a start, really.''
Voussoir (race 5) looms as the best of Kennedy's other runners today.
''It's not a really strong field and he's shown a little bit. He's probably a really good runner,'' Kennedy said.
Shirley Brook and Eldante represent Kennedy in race 6, a rating 65 2000m, and Kennedy clearly leans towards Shirley Brook of the two after her seventh at Waikouaiti on New Year's Day.
''She went a good race at Waikouaiti. She wasn't that far away.
''She didn't get a lot of luck down the straight, to be fair. She'll race right on the speed, just behind them and hopefully finish them off.''
Eldante needs to overcome her claustrophobia to show her best on race day.
''She can gallop, but she's really field-shy.
Drumregal drops back from open company on Boxing Day to the rating 85 grade today, and Kennedy was pleased with her dip into the big time, running seventh to Toma Valea.
''It's probably a big drop back in class here and she's [carrying] 54kg and [has] a good barrier draw (4). She's a good runner's chance.''
Young Issy (race 4) is green and will improve with the run, but has some ability, while Sparks Fly (race 9) needs to produce a decent performance in a weak field to justify her continuing on as a racehorse.