The Last Chronicle of Barset by Anthony Trollope

The Archdeacon, although allowing that Grace is a lady, doesn't think her of high enough rank or wealth for his widowed son; his position is strengthened by the Reverend Mr Crawley's apparent crime. Almost broken by poverty and trouble, the Reverend Mr Crawley hardly knows himself if he is guilty or not; fortunately, the mystery is resolved just as Major Grantly's determination and Grace Crawley's own merit force the Archdeacon to overcome his prejudice against her as a daughter-in-law.