An Hour Unspent by Roseanna M White

Evelina Manning is the daughter of a master clock-maker and a frustrated society lady.  Evelina feels passionately about women's rights, but longs to be happily settled with her aristocratic fiance.  All her plans tumble apart when WWI starts and Evelina's fiance decides to enlist rather than marry her.  In walks Barclay Pearce, a scrappy ex-thief who finesses his way into Evelina's father's good graces and Evelina's life.  As WWI heats up can Evelina look past Barclay's past and trust him when she needs him most?

This is a better-than-average religious historical romance.  It has the slightly sappy undertone one would expect, but it is less cloying than in many Christian romances.  The setting is interesting and there is a decently engaging background plot involving spies steeling plans to a secret weapon.  It is listed as the third in a series, but the first two books feature other characters, so this one stand alone just fine.  It was just the kind of book I needed after reading the heavier, When Breath Becomes Air, like vanilla ice cream with strawberries after a nice hearty dinner.