Dust by Susan E.B. Schwartz

When it comes to finding dirt, Evan Reed is the best in the business. She’s a dust-buster—a paid operative hired by political campaigns to vet candidates. She’s also a foul-mouthed, cranky ex-Catholic, attempting to raise a fourteen-year-old daughter on her own. When she’s hired to investigate the background of a squeaky-clean and charismatic senator who might just be the next president, the last thing she expects to uncover is a murder. Evan’s life is further complicated when she meets the senator’s reclusive wife—who happens to be hiding some dust of her own.