The wife of Mitt Romney co-owns a horse that was ridden by which rider in the 2012 summer Olympics ?
Jan Ebeling
Title: Ann Romney
Passage: Ann Lois Romney (née Davies; born April 16, 1949) is the wife of American businessman and politician, Mitt Romney.  From 2003 to 2007, Romney was First Lady of Massachusetts, while her husband served as Governor.
Title: Stefano Brecciaroli
Passage: Stefano Brecciaroli (born 17 November 1974 in Rome, Italy) is an Italian Olympic eventing rider.  He competed at four Summer Olympics (in 2004, 2008, 2012 Summer Olympics and 2016.  He best finished 5th in team eventing at the 2008 Olympics.  Meanwhile, his current best individual Olympic placement is 19th position from 2012.
Title: Rafalca
Passage: Rafalca is a dressage horse co-owned by Ann Romney that performed in the equestrian competition at the 2012 Summer Olympics, with rider (and co-owner/trainer) Jan Ebeling.
Rafalca Ann Romney