A Colorado sheriff takes in his niece upon the death of her parents, but a beautiful nanny throws an additional wrinkle into the mix, in Brenda Jackson's Duty or Desire.
Jackson is a popular African-American romance writer whose "Westmoreland Saga" features an extended family of lawmen, ranchers, cowboys, Navy SEALS, and sometimes a combination of one or more of these. They are typically avowed bachelors who fall in love with a Harvard PhD, a prominent magazine editor, or a Hollywood star (just to mention some of the characters from other novels who appear here).
The romance aspect is never in doubt, but the setting is faintly sketched in (the nanny has a father who is a "business tycoon", but what his business is never gets mentioned) and the tension is mild (the top cop in Denver's most serious case is finding out who is trying to spook an old lady into selling her house).
But that's not what these novels are read for, and Jackson is a top writer in her field.
I listened to this on audiobook from the Henry County-New Castle Public Library in New Castle, Indiana.