Funeral in Blue (William Monk, #12) by Anne Perry - Goodreads

Dr. Beck quickly becomes the prime suspect. To clear his name, William Monk, Hester, and their friend Lady Callandra Daviot must unravel Elissa's secret past, which leads them all the way to the 1848 revolution in Vienna. Key Characters

One is an artist's model; the other is Elissa Beck, the wife of Kristian Beck, a prominent surgeon and friend of Monk’s wife, Hester.