Death of a gigolo
(Book)

Series numeration from Goodreads.com.

"Daisy Kincaid is in her sixties and heiress to a fortune. Now she wants to make a name for herself as a romance author...with a little help from Jaine, that is. As Jaine labors away on love scenes, she gets to know the wealthy woman's gentleman friend, her household staff, and her social circle--every one of whom is horrified when Daisy falls under the spell of a much younger stud named Tommy, a rude, crude lothario who's made himself a fixture in Daisy's Bel Air mansion. After Tommy and Daisy shock everyone by announcing their engagement, it doesn't take long for someone to stab him in the neck--with the solid gold Swiss Army knife that Daisy gave him as a gift. But to narrow down the list of suspects, Jaine will have to put a bookmark in that love story--and focus all her creative talent into untangling a tale of money and murder..."--Back cover.