Chance, Maia. Discreet Retrieval Agency mysteries #2

"After her philandering husband died and left her penniless in Prohibition-era New York, Lola Woodby escaped with her Swedish cook to the only place she could--her deceased husband's secret love nest in the middle of Manhattan. Her only comforts were chocolate cake, dime store detective novels, and the occasional highball (okay, maybe not so occasional). But rent came due and Lola and Berta were forced to accept the first job that came their way, ultimately leading them to set up shop as a Discreet Retrieval Agency, operating out of Alfie's cramped love nest. Now they're in danger of losing the business they've barely gotten off the ground--they haven't had a job in months and money is running out. So when a society matron offers them a job, they take it--even if it means sneaking into a detox facility and consuming only water and health food until they can steal a diary from Grace Whiddle, a resident at the "health farm." But barely a day in, Grace and her diary escape from the facility--and Grace's future mother-in-law is found murdered on the premises. Lola and Berta are promptly fired. But before they can climb into Lola's red and white Duesenberg Model A and whiz off the property, they find themselves with a new client and a new charge: to solve the murder of Grace's future mother-in-law"--