The American Agent by Jacqueline Winspear

The American Agent is the latest Maisie Dobbs adventure. We're now in the middle of WW2 and Maisie and her best friend Priscilla are ambulance drivers, helping the victims of the nightly bombings in London. One night, an American reporter named Catherine joins them to get a bird's-eye view for a story. Shortly thereafter, Maisie's investigations firm is hired to find out who murdered Catherine. Most of the book is devoted to the case. But there are 2 other subplots. One involves Anna, the little refugee girl that Maisie is trying to adopt and the other involves Mark Scott, an American agent who was introduced in an earlier book. He is nominally involved with the murder investigation though he mostly keeps popping up as a possible romantic interest for Maisie.

As much as I love this series, the one thing I don't like is the romantic developments, which the author doesn't seem to be much interested in writing. Maisie's whole marriage to her late husband James was over before it started. And this romance seems to be taking off based on who knows what?
Other readers of this series have told me that they too would like to see Maisie enjoying a little happiness.