How we cite our quotes:
You have anticipated, mother, that I [Arthur] decide for my part, to abandon the business. I have done with it. [...] I have lived the half of a long term of life, and have never before set my own will against yours. I cannot say that I have been able to conform myself, in heart and spirit, to your rules; I cannot say that I believe my forty years have been profitable or pleasant to myself, or any one; but I have habitually submitted, and I only ask you to remember it. [...] Mother, I have yet something more to say. It has been upon my mind, night and day, this long time. It is far more difficult to say than what I have said. That concerned myself; this concerns us all. [...] You knew my father infinitely better than I ever knew him; and his reserve with me yielded to you. You were much the stronger, mother, and directed him. As a child, I knew it as well as I know it now. I knew that your ascendancy over him was the cause of his going to China to take care of the business there, while you took care of it here (though I do not even now know whether these were really terms of separation that you agreed upon); and that it was your will that I should remain with you until I was twenty, and then go to him as I did.' (1.5.27-35)
Arthur spells out the whole dynamic of his family here. He and his father weakly submitted to whatever his mother demanded, and he hasn't had any model for how to deal with her aside from just buckling under.
What [Little Dorrit's] pitiful look saw, at that early time, in her father, in her sister, in her brother, in the jail; how much, or how little of the wretched truth it pleased God to make visible to her; lies hidden with many mysteries. It is enough that she was inspired to be something which was not what the rest were, and to be that something, different and laborious, for the sake of the rest. [...] With no earthly friend to help her, or so much as to see her, but the one so strangely assorted; with no knowledge even of the common daily tone and habits of the common members of the free community who are not shut up in prisons; born and bred in a social condition, false even with a reference to the falsest condition outside the walls; drinking from infancy of a well whose waters had their own peculiar stain, their own unwholesome and unnatural taste; the Child of the Marshalsea began her womanly life.
No matter through what mistakes and discouragements, what ridicule (not unkindly meant, but deeply felt) of her youth and little figure, what humble consciousness of her own babyhood and want of strength, even in the matter of lifting and carrying; through how much weariness and hopelessness, and how many secret tears; she drudged on, until recognised as useful, even indispensable. That time came. She took the place of eldest of the three, in all things but precedence; was the head of the fallen family; and bore, in her own heart, its anxieties and shames. (1.7.32-34)
This is such a poignant moment, the way the narrator tries to show us just how little exposure to anything outside the prison Little Dorrit has had. She just somehow innately senses that she has to be better than this place and its values. There is a similar moment a little while later when she comes to Arthur's sad little apartment, which to her seems like a grand palace.
[Little Dorrit's] look at her father, half admiring him and proud of him, half ashamed for him, all devoted and loving, went to [Arthur's] inmost heart. (1.8.34)
What an array of adjectives here – admiring, proud, ashamed, devoted, loving. These words pretty much encapsulate the relationship between Dorrit and Amy. Also, isn't it odd how much Arthur is into this display? What will Amy be like toward him later in their lives?