Star Rider - a Starlight Adventures Game Book No. 1
Puffin, Harmondsworth, 1985, illus Peter Wilks
The heroine inherits some money, buys a horse and enters the world of professional horse competition. Riddle of the Runaway turns the reader into a young detective who travels to the United States through New Orleans clubs and Las Vegas casinos to find a wealthy rock musician who has disappeared. School Library Journal
Carole Carreck wrote one title for the Starlight Adventures series. This was a British series which promised "ambition, mystery and romance." I can find nothing else listed anywhere for the author, so I think it’s possible it was a pseudonym.