The novel was pulled from Bronte's own experiences as a governess and the book reads like someone relieved to open up. There's nothing like coming home from a bad day at work and saying "you'll never believe what happened this time...". A governess lives in her employer's house, as servants did, but as an acknowledged gentlewoman she also could not form bonds with other household staff. It was a lonely position, and a difficult one if your authority is limited to the boundaries that Agnes' employers gave her. There would have been no opportunity to decompress or garner sympathy from a friend except through letters - and it becomes clear that Agnes is not the sort of woman who would allow herself that kind of luxury.
Her charges are cruel, little monsters - children - or spoiled and inattentive. She is expected to correct faults and educate, but without inconveniencing them in any way. The contradictions, the hypocrisy, and again and again, the isolation and lack of understanding are insurmountable obstacles. Her only outlet to us, her readers, is a modern one: sarcasm. Agnes' sarcasm and irony nicely offset her faith and lovelorn denials. My impression is that Agnes found strength in her religion, but sanity in pointing out the often bizarre behavior and expectations of her employers and their families. As bleak as her situation can be, there are smiles and I could see the long suffering Agnes rolling her eyes behind her mistresses' back after yet another contradictory order.
Agnes Grey deals with grim realities which is a refreshing antidote to my other Victorian reading proclivities. Of her two novels this one feels superior for its simpler structure and the success of Agnes as a character who faces stern tests of character, shouts down doubts about herself, and persists.