Aidan O’Brien’s Classic heroine Mother Earth is primed to bid for her third Group One of the year in the Coolmore America “Justify” Matron Stakes.

Mother Earth, who has already put the 1000 Guineas and Prix Rothschild titles in the Ballydoyle cabinet this year, will be joined in a 13-strong field by O’Brien’s Empress Josephine – an Irish Guineas winner in May – and a third stablemate, Friendly.

Strong opposition for them at Leopardstown on Saturday includes Paddy Twomey’s dual Group Three winner Pearls Galore, Ger Lyons’ Acanella and Willie McCreery’s Epona Plays.

Another out to make her seniority count is Ed Walker’s four-year-old Dreamloper, who crosses the Irish Sea from Lambourn after managing only fourth in Newbury’s Hungerford Stakes last time but as an emphatic Group Three winner at Ascot before then.

Last year’s winner Champers Elysees has run well in defeat several times for Johnny Murtagh this summer – while old rivals Shale and Pretty Gorgeous, for brothers Donnacha and Joseph O’Brien respectively, are also very much in the reckoning.

Mother Earth is nonetheless clear favourite to augment her already successful campaign, under Ryan Moore.

O’Brien said: “She is a lovely filly who probably doesn’t want to be in front too long.

“She’s a great traveller and very enthusiastic and usually very consistent.”

As well as her two triumphs this summer, Mother Earth has performed with significant credit in three defeats – at the top level throughout.

Empress Josephine has twice failed to reach the frame in Group One company since her Classic win at the Curragh – including when upped to 10 furlongs last time in the Nassau Stakes at Goodwood.

O’Brien said: “Empress Josephine went a mile and a quarter the last day, and it just didn’t work for her – they didn’t go fast enough for her.

“We’re going back to a mile with her and will ride her a bit patiently this time.”

Dreamloper has established her niche at a mile or seven furlongs – but will not appreciate any easing of the ground from the current good.

“She wants any rain to stay away,” said Walker.

“She’s really got her act together this year and was brilliant in the Valiant (at Ascot).

“The race unfolded the wrong way for her at Newbury, but still she did not disgrace herself.

“Back to a mile, hopefully there will be a good pace and she can switch off – then I think she’ll run a big race. It’s very exciting.”