In any other context, I would've been embarrassed by [Sam's] nakedness, but here, his skin smeared with blood and dirt, it just made his condition seem more pitiful. (12.48)
We see early on that Grace is compassionate toward the pain of others. We're not sure if it's more impressive that she managed to keep her cool because Sam is “her wolf” come to life, or if that's the reason why she's so compassionate in the first place. Would she have treated, say, Jack the same way?
I didn't want to say something [about Sam's scars] because, really, that'd be just as bad as Sunny, assuming that he'd tried to kill himself. (14.48)
Grace is surprisingly compassionate for her age. Most people would be like, what are those? How'd you get those? What is wrong with you?
“Sorry about tonight,” [Grace] whispered. “I don't mean to push your boundaries.” (27.33)
This is a surprisingly adult conversation Grace has with Sam about boundaries. She's trying her best to understand him and to make him comfortable, which is something that is at the very root of compassion.
“Who could do that to a child?” (38.1)
Grace's mother is very sympathetic toward Sam's past trauma. Now we see where Grace gets it from. Of course, Grace's mother almost cancels it out by saying Sam could go psychotic, but a bit of compassion is better than none, right?
I should have been angry. Furious at having my life ripped away from me. But there was just white noise inside me, a dull hum of nothingness. (44.40)
This is Sam's reaction to the realization that Beck turned him into a werewolf on purpose. Any other wolf might have gone into a violent rage over this, but Sam is fairly peaceful about it. We're not sure if this is forgiveness or just numbness.
“I want to know everything about you. It can't be that hard to understand.” (46.10)
Again, we see Grace's compassion. She's not doing this because she's a nosy girlfriend. She's asking to meet Beck, Sam's father figure, because she really wants to understand where he comes from.
“I wished with all my heart that [Sam] was just a normal boy, so that I could storm away with my pride and indignation. But he wasn't. He was as fragile as a butterfly in autumn, waiting to be destroyed by the first frost. (46.29)
This is Grace's thought process after an argument with Sam. She gets over it quickly, but doesn't it seem like Grace only forgives Sam because he's a fragile werewolf? Would they still be fighting if he were a human boy?
“Beck didn't have to do what he did. My parents did. They thought I was a monster. They were afraid.” (46.34)
This chapter is chock-full of forgiveness. It's incredible that Sam is able to forgive his parents after they tried to kill him. But he still hasn't yet grasped Beck's point of view on the situation. Beck felt he did have to do what he did, both for Sam and for the the good of the pack.
“[Sam] puked all over the carpet. But that's okay because I like having my parents pissed at me.” (51.3)
This is about the biggest admittance of 'forgiveness' we're going to get out of Isabel. She may joke about it, but we get the feeling she really does care about Sam.
“I made a personal hell for [Sam].” (58.33)
It takes awhile, but Beck finally realizes not just what Sam is going through, but what he put Sam through. If he had been able to put himself in Sam's high tops when Sam was seven, he might not have bitten him.