Ashley and Lisa McKay (18) are in the final month of a three-month probationary period with their trainer father, Russell, at Ashburton as a lead-up to race riding..
The McKay family shifted from Gore a month ago to provide opportunities for the twins to pursue careers as jockeys.
"We needed to get the girls riding at trials to get the experience," their mother, Robyn McKay, said.
Ashley has ridden in 17 trials and Lisa in five.
"The senior riders have been marvellous in taking the girls through the riding experience at trials," she said.
Their father has 11 horses for the twins to ride in work.
He served his apprenticeship as a jockey with Gerald Robertson at Wyndham and rode seven winners before he became too heavy.
Decked out in riding helmets, Ashley and Lisa are nigh impossible to distinguish, which could keep racing followers and officials guessing.
"We know them when they are riding work as Lisa has a pink hat cover and Ashley has a green and blue striped cover," Robyn said.
Identical twin brothers Keil and Sean Collins have ridden in NZ in the last decade.
Keil, who is still riding, has ridden 130 winners.
He is based at Foxton with the stable of David Howarth and Matt Dixon.
He did his time with Murray Baker, Dianne Sargent and Grant Searle.
Sean rode 120 winners, but increased weight forced him aside.
He served his apprenticeship with Bruce Marsh and Brent Hrstich.
Twins Shari and Karen Knapp rode in the Pacific Northwest region of North America in the early 1980s.
They finished first and second in a race Portland Meadows in 1982, according to the internet.
