Kellie Cerin, the wife of Southern California trainer Vladimir Cerin, died Thursday as a result of injuries suffered in a fall. The accident happened in Mexico, where the couple was vacationing. Vladimir Cerin said his wife of 17 years "tripped on a step and hit her head." Kellie Cerin was actively involved in her husband's stable, spending several mornings a week at the barn and working with the horses that the couple kept at their home near Santa Anita. Kellie Cerin was also active as a horse-riding teacher. "She was a great horsewoman in her own right and a great trainer of show jumpers," Cerin said Friday by phone from Mexico. A funeral is scheduled for 5:30 p.m. Wednesday at the Church of the Good Shepherd, 400 W. Duarte Road, Arcadia, Calif. In lieu of flowers, Cerin requested that donations be made to the California Equine Retirement Foundation.