Allison Montclair: The Unkept Woman
This series goes from strength to strength. Set in just post WWII London, Iris Sparks and Gwen Bainbridge run The Right Sort, a marriage bureau (apparently something that existed at the time). Iris worked in intelligence during the war, and Gwen, a daughter of privilege, is a bereaved widow who lives with her in-laws and young son as they have had her declared mentally incompetent. The two find solace and purpose in running a business together, and my only actual quibble with this book was that there was really none of the marriage bureau in the plot (or very little).