Characters:

Derek and Elaine Griffen - Ashleigh's parents, experts in breeding horses
Caroline and Rory Griffin - Ashleigh's older sister and younger brother
Mike Reese - Ashleigh's husband in later books; he inherits Whitebrook Farm
Christina Reese - Mike and Ashleigh's daughter
Melanie Graham - Mike and Ashleigh's niece, Christina's cousin

Samantha McLean - Daughter of the former Townsend trainer, who replaced Charlie Burke as head trainer at Whitebrook Farm
Ian McClean - Samantha's father
Cindy Blake - runaway who is adopted by the McCleans
Tor Nelson - Samantha's husband in later books; he rides and trains showjumpers
Charlie Burke - An ex-trainer for Townsend Acres, who moves to Whitebrook Farm to help Ashleigh train Wonder and her descendants.
Ken Maddock - Head trainer for Townsend when the Griffens first move there
Jilly Gordon - Jockey

Clay Townsend - owner of Townsend Acres
Brad Townsend - Clay's son
Lavinia Townsend - Brad's wife
Parker Townsend - Brad and Lavinia's son