I have seen some people say that Grace Livingston Hill's heroes and heroines are often priggish; I've read dozens of GLH's books and always disagreed with that. While her heroes and heroines try to achieve a high moral standard, and her heroines can be woefully naive, they're not generally judgmental of those who are not actively trying to do harm.
But the hero (or one of the two heroes) of this one seriously got on my nerves, and frankly, about halfway through the book I had him pegged as a big ol' prig, because he was always bashing his sister (in his thoughts, not directly) for everything from wearing make up to having a poor fashion sense to just plain ol' not being the sister he wanted. His best buddy and most of the other Christian characters, however, are considerably more rational, and the hero finally gets a clue and recognizes he's been "a bounder" for his past attitudes toward sister and mother, and thanks his best buddy for encouraging him to do right.
His best buddy promptly assures him he'd have done the right thing no matter what, but personally, I have my doubts. ;)
Also did not expect the big climactic scene to go as it did. Considering how many books GLH cranked out, and how many of them I have read, it's nice to know she can still surprise me. Possibly because I read her stuff when I'm too tired for any of my other reading, but OTOH I do that with Jayne Anne Krentz as well, and JAK is so predictable I don't dare read more than one or two "new to me" books by her a year, or the sameness makes me crazy.
I think that because GLH doesn't focus so tightly on her hero and heroine and their romance, the fact that a lot of heroes and heroines are interchangeable isn't as annoying as it is with many other romance authors. GLH was not the genius that Georgette Heyer was, but those are the only two romance authors I've run across whose new-to-me novels can feel new even after having read ten or more of their novels. All the other romance authors I've quite liked get to be same-old same-old pretty quick.