I also found it unrealistic that Pearl would forgive her mom so quickly. I told my mom there's no way I would forgive her if she had done that to me, and she laughed and agreed with me. Haha. I agree that Mia's redemption was unearned. Granted, this is the only episode of the series where I found her remotely tolerable, but I still kinda hate that she gets a happy ending. Nonetheless, that's life.
In fact, what I appreciated most about the ending to the series is that it perfectly mirrored real life. Some people never pay for their misdeeds. Some people are awarded for bad behavior. Some people eventually lose everything they worked so hard to achieve. Innocent people pay a tragic price.
I thought the scene building up to the fire was fantastic. That's one of the best scenes I've seen on TV in a while. It was perfection. Writing, directing, acting -- especially Reese. My goodness, when she yelled, "YES, YOU ARE!!!!!" even *I* was scared. The acting (with a small exception for KW) was the best part of the entire series, IMO. I would love to see nominations come awards time.