She wasn’t in prison, but she’d been held hostage by Bellatrix. In the books she returns to school; why she comes out of hiding to do that is not explained, but it’s easy to fanwank away - she wanted to be with her Dad for a while, which then entailed her going to school (since it had been made mandatory); keeping her secret was too hard once the threat to her was gone; she came out of hiding to save her Dad.
Yeah, that really bothered me too. Surely they can’t have thought nobody would notice? When the sorting hat’s put on Lily’s head there’s a close-up of her face with her big brown eyes. And this comes just after a close-up of Daniel Radcliffe’s blue eyes with Snape saying they are his mother’s eyes. The YoungLily scenes are Snape’s memories, so he wouldn’t have remembered them as being a different colour to Harry’s. Same eyes does pretty much always mean same colour, but they’re a very different shape anyway.
Or just cast an actress with eyes the same colour as Daniel Radcliffe’s, or close. Hair can be dyed, blue eyes are common, and it’s not like every 10-year-old girl in the world wouldn’t have been queuing up for the part. The books said green, but that’s not important if it’s too difficult to film; what was important was having the eyes be the same colour in the characters where having the same eyes is a really, really big deal.
I hope someone asks the director why he did this, at some Comicon or something. I’d also be happy for them to be edited for a later edition of the film on DVD.
That’s the only serious nitpick I have, anyway. There are a few things I would have liked to have seen done differently maybe, but overall I loved the movie so am happy with it as it is.
Actually, in the book, it’s explained that the gang still at Hogwarts used the coins they had from the Dumbledore’s Army days, that they used to notify each other when there would be a session.
Everyone came back by apparating (or whatever) back to Aberforth’s bar, and crawling down the same passage to the Room of Requirement.
Luna was still, I believe, at Shell Cottage when Harry and gang staged the Gringott’s caper - and the rest of the events of the book all happened in the 12ish hours after that. She never returned to school after escaping Bellatrix (well, not until the final few hours when the DA folks were summoned).
One thing that annoyed me about everyone coming back: they showed Cho Chang as being in the group already AT Hogwards (she was a year older than Harry and would have finished school up the year before).
I read in one of JK Rowling’s interviews that Ron ends up working at the joke shop with George (which will put a stop to his complaints about never having any money!)
Mama Zappa already explained this. Here’s Luna’s timeline in book 7.
Luna and father are invited to Bill’s wedding.
At the beginning of the school year, she goes back to Hogwarts, causes trouble with other DA members (She might’ve been one of the people caught trying to steal Gryffindor’s sword.)
Gets arrested/kidnapped to keep her father in line and stop him from supporting Harry Potter in the Quibbler. This happens close to when Harry, Ron and Hermione go to see Xenophilus at his house, asking about the Deathly Hallows symbol. At that time Xenophilus is printing the first Quibbler issue which would be denouncing Harry Potter.
After her arrest, Luna is kept in the Malfoy’s dungeon/basement along with Ollivander.
Once freed by Dobby, she stays at Shell cottage, while Harry et al. leave to rob Gringott’s.
Harry et al. go to Hogsmeade, are brought into the castle via secret passage / Neville / Aberforth / painting of Ariana Dumbledore. At that time Neville uses his old D. A. coin to round up members of the D.A. A bunch of D.A. members, including Luna, Weasley twins, Ginny, Cho Chang, Dean Thomas, etc. show up in the Room of Requirement hideout while Harry & friends are talking to the students in the Room of Requirement, before Harry goes off to look for Ravenclaw’s diadem.