I love all of Lilly's nicknames omg. She looks fairly well put together on top of that, but her skin tone seems sort of odd to me? You say it's pretty light but not ghostly - is it glowing with health? More of a porcelain colour? Is she ashamed of her scars? Does she cover them up so she doesn't have to look at them? The 'Loneliness terrifies' bit in her motivations definitely hit me pretty hard - she seems like such a sweet girl. How much does she depend on her friends - emotionally, physically, mentally, etc.? That could definitely put a strain on their relationship. Her education could stand to have a little more meat in it. How is she doing in school, which grade is she in? (I'm assuming they were somewhere in america before they were sent to the other universe, since you mention high school?) Was she an all a's student or someone prone to boredom for being smart? You could also mention how she's doing in the new universe as well! All in all, I love her and want to protect her.
Like @BookNerd said, Grant's on private. :(
For Trinity, what does she introduce herself as - her actual name, a nickname that stems from it, or a nickname that is completely different? What colour brown is her hair? Her scar is a really neat touch, though, I love that it implies she was running across fields - probably at night - as a kid. Her mannerisms could also use a bit more meat in it - how does she stand? How does she talk? Does she have any fidgets aside from playing with her hair or were they discouraged? Is being polite more of a motivation than being nice for her? Her politics section could use a bit more, as well. Most teenagers I know are pretty politically motivated, even if it's just to shoot down views they don't agree with. For her background, does she resent the friend's father for surviving? Does she feel guilty about it? I love her as a character, but she feels far more like a background character than a protagonist at the point she's at now.
(i'll get to the other three in a sec, but i gotta take a mo' to breathe ^^; )