Deliberate Values Dissonance: The whole effect of the film is to make the modern Western audience roil with indignation of what kind of Western society would treat young women as potentially lifelong prisoners and slaves for a self-righteous morality.
Margaret slips into this a few times. She does have some sympathy, taking Crispina under her wing. But when she finds out Bernadette took Crispina's St Christopher medal she physically attacks her and is enraged the other girls don't join in. She even yells at Crispina for not being mad at Bernadette, Crispina only being glad that the medal was found.
Bernadette is an even more strong example of this, by shutting herself off from the other girls in an attempt to cope. She knew that Crispina's St Christopher was the only thing giving her hope, but she keeps it from her even after Crispina attempts suicide twice. She later tells an elderly dying inmate who wants her to stay by her bedside that nobody cares about her and that she should hurry up and die.
Fridge Horror: Margaret's cousin apparently got away scot-free with raping her; we never see him get punished, and their families may well have believed she led him on. Now that he's seen there are no repercussions for his actions, how long before he does it again?
Bernadette. You can understand her frosty attitude when you consider she's an orphan and only been sent there because she talked to boys too much. Add that to the crap she has to go through in the laundry and you still want to hug her even when she's snapping at people.
Katy also qualifies. She was signed in as a young girl and stays in the laundry until her death as an old woman. She is cruel to the younger girls and rats out Bernadette to the nuns, but as a product of years of Stockholm Syndrome she truly believes the nuns know best and are kind and Godly at heart. When it's revealed how long she's been there, and the tragic circumstances of her family giving her up and her losing her baby, it's clear she's Not So Different.
Unintentionally Unsympathetic: Margaret when her brother signs her out. The little speech she gives to the rest of the girls comes across as incredibly callous - since she now gets to be freed and it seems like she's rubbing it in their faces that they can't be. Then she snaps at her brother - who has done nothing wrong to her at all - "you didn't grow up fast enough!"
Rose and Crispina, mothers of children they were forced to give up. Crispina only ever got to see her son from a distance at the laundry gates and Rose isn't reunited with hers until he's thirty years old.
Margaret, raped at a wedding by her own cousin. She is taken away to the laundry by her own father the very next day, as her family believes she coerced him into sex acts.