These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Moment of Heartwarming: Meg using the blue stones on Lowrie and Franco instead of herself, saving their lives. The act of mercy towards the latter is also incredibly important, as it's just enough to get Meg into Heaven.
Meg walking into Heaven and smelling her mother approaching.
Meg helping Lowrie finally kiss his One True Love Cicely Ward, the one he let get away and is now a famous television host. In story it also acts as an actual CMOH, a rare act of pure goodness that actually blasts anything demonic nearby all the way back to Hell. Even better, Lowrie's last thought in the story is how he'll get back in touch with Cicely.
Informed Wrongness: Apparently, the trick Meg pulled on her stepfather (see "Magnificent Bastard" below) was wrong (so wrong that it's part of the reason she's in danger of going to hell and the main reason Satan wants her so badly), even though it saved her from being adopted by a cruelly abusive guardian. How someone in her position should solve the problem instead is never clarified by the book.
Though it's implied Satan wants her less because what she did was evil compared to how creative it was and just how much it made Franco hurt.
Magnificent Bastard: Meg pulls an absolutely stunning gambit against her abusive stepfather that ultimately ruins his credibility, humiliates and discredits him in front of his peers, and frees Meg from the prospects of being adopted by him, involving running a series of tapes showcasing Franco's pathetic life at home and his abusive behaviours towards his surrogate daughter. This does come back to bite Meg however, as despite Meg's justifications, it's still stated to have cost her a lot of negative karma. It says something that this gambit is exactly why Satan wants her for Hell.