Death Was in the Blood — Linda L. Richards

When her father killed himself after the stock market crash of 1929, Kitty Pangborn's life changed forever. Raised to be a debutante, she was forced to get a job as a secretary for Los Angeles P.I. Dex Theroux where her biggest concern is making sure her boss solves enough cases to keep her in paychecks--though that's not always as easy as it sounds.

Set during preparation for the 1932 Olympic games, in Death Was in the Blood, Kitty finds herself trying to discover who is threatening a young equestrienne aiming to be the first horsewoman to compete at the Olympic level. Kitty finds herself back in the social class she was raised to, only now she's expected to come in the service entrance.