Definitely Dead - Empty Nest Mysteries, #1

An homage to Dashell Hammet's Thin Man movies with a modern day spin on Nick and Nora Charles. When her career is outsourced to Asia, fledgling romance author and empty-nester Gracie Elliott wants a job that will allow her time to write. So she opens Relatively Speaking, becoming a wing woman to the senior set. Since her clients need several hours each morning to find their teeth, lube their creaky joints, and deal with lower GI necessities, and they always turn in after the early bird specials, she has plenty of time to pen her future bestsellers. Gracie deliberately avoids mentioning her new business venture to husband Blake until after she signs her first client.
Blake joins the company as a not-so-silent partner, tagging along to make sure Gracie doesn't cause a septuagenarian uprising. When Client #13 is found murdered in the parking lot behind the Moose Lodge, Gracie knows, no matter how much Blake protests otherwise, she can't wait around for the police to find the killer if she wants to save her livelihood.