The North Yorkshire trainer, who saddled three winners at Wetherby’s two-day Christmas meeting, wants to see if the mare can stay two-and-a-half miles.
She will also be racing against other mares in the chase at Doncaster and Kirby did not want to take any chances at Wetherby in a race won by Sue Smith’s Cracking Find.
He said he did not want to risk aggravating a tendon injury that Lady Buttons suffered in the past on similar going, and believes the going will be good on Town Moor.
Meanwhile, Malton trainer Brian Ellison confirmed that Definitly Red, already the winner of big races at Wetherby and Aintree this season, will have two racecourse gallops before lining up in the Cheltenham Gold Cup in March.
He says the gallops will take place towards the end of January, and also in February, before the showpiece race in which Definitly Red was sixth last year on unsuitably soft going.
Ellison said the three-mile-plus steeplechasing division was “wide open this year” following the King George VI Chase win of Clan Des Obeaux, and that he could not be happier with his horse’s form or fitness.