In this view they were sedulously abetted by their mothers, aunts and other elderly female relatives, who all shared Mrs. Archer’s belief that when "such things happened" it was undoubtedly foolish of the man, but somehow always criminal of the woman.
There are no more uses of "abet" in the book.
Show samples from other sources
The man who could not be discourteous to a ground-squirrel had sat in the courthouse abetting the cause of grubby-minded little men.
Harper Lee -- Go Set a Watchman
Not telling her is tantamount to aiding and abetting the enemy.