Dying in the Wool by Frances Brody

In 1922, presumed widow Kate Shackleton craves her independence, even though her mother would like her to stop private investigating and concentrate on more feminine pursuits. Kate agrees to help an old friend, Tabitha Braithwaite, find out what happened to her father, Joshua. He disappeared six years ago after it appeared that he attempted suicide. Kate and her assistant, Sykes, immerse themselves into both the public and private lives of the people from the local mill (Joshua was the owner), in order to find out what happened to him.  As questions are asked, danger descends upon those involved. Dying in the Wool is the first book in the Kate Shackleton series. It's a good choice for those who enjoy the Maisie Dobbs series by Jacqueline Winspear and the Bess Crawford series by Charles Todd.