Merla Zellerbach wrote a mystery series featuring PR amateur detective Hallie Marsh. All include a fun look at San Francisco, relationships, and San Francisco society. The books reflect different aspects drawn from her personal life from fundraising to breast cancer to self-help to SF personalities. Merla Zellerbach wrote several novels and non-fiction, was editor of the Nob Hill Gazette, had a column in the SF Chronicle, but she didn't begin writing mysteries until she was 82.
Read an article (2012) about her and her Hallie Marsh mysteries in the Stanford Alumni Magazine here. From the article: How does she explain all those romances in her books? "Hard-core mystery buffs and purists of the genre want me to choose between romance and mystery. But then I would ask: What is death without life? And what is life or death without love?"