Great Heavens and Colliding Worlds have been supplemented for the Darley Irish Oaks at the Curragh on Sunday.
They are among 11 possibles for the fillies' Classic, along with Investec Oaks heroine Was and impressive Ribblesdale Stakes scorer Princess Highway, following the confirmation stage.
The John Gosden-trained Great Heavens is a full-sister to King George and Coral-Eclipse hero Nathaniel and booked her place in the Group One with an emphatic victory in the Lancashire Oaks.
"Everything that's been thrown at her she's taken quite easy in her stride," jockey Rab Havlin, who rode her in that race at Haydock, told At The Races.
"It's another step up again at the weekend so hopefully she will do the same again.
"She went a solid gallop (at Haydock) and felt as though she could have gone round again. She really handles the soft ground well and seems to be improving all the time."
The Edward Lynam-trained Colliding Worlds is taking a massive leap in class, having won a maiden over nine furlongs at Leopardstown on the latest of her two career starts.
However, connections are happy to let her have this opportunity at the top level, especially as conditions are likely to suit the daughter of High Chaparral.
"She won nicely last week in maiden company. It's a big step up in class for her, but her owner is keen for her to take her chance," said the County Meath trainer.
"He has all the family and if we're not in we can't win so we have supplemented her.
"She's a filly I think will be better as a four-year-old. It's a huge ask for her, but she's proven on soft ground and her owner Jimmy Long is a great supporter of Irish racing.
"He's very keen she has a go and we've nothing to lose."
Lambourn trainer Hughie Morrison has never been one to shirk a challenge and Shirocco Star is all set to travel.
Placed in the Oaks and the Ribblesdale, she is without a win this season but already looks a valuable broodmare for her owners, Helena Springfield Ltd, who have already enjoyed one big day in Ireland this season with Izzi Top in the Pretty Polly.
"We've left her in the Irish Oaks and at the moment we're heading over," said Morrison.
"She also has an entry at Newmarket, but that's just in case the weather deteriorates any further.
"She goes on all ground, though, so soft ground is unlikely to put us off.
"I hope she runs well as she's thriving on her racing at the moment, there's certainly no sign that it is catching up with her at home, despite having three hard races in a relatively short spell of time. You certainly couldn't question her enthusiasm.
"We're keen to go as this is the last chance she'll get to take on three-year-olds and she warrants going.
She might be third or fourth in the betting and we've plenty of ground to make up on Dermot Weld's filly (Princess Highway) but the owners are keen to go and racing is about competition.
"If people like us didn't have a go you end up with races like the Irish Derby and nobody really wants to see that again."
As well as Was, Aidan O'Brien can also call on Betterbetterbetter, Demurely, Devotion, Twirl and Wonderful.
Jim Bolger's Livia Galilei completes the line-up.
