Re: Lily and Luna
"It's very nice to meet you," Luna returned, meaning it. This wasn't easy, knowing what she knew. Being thoughtful and a Ravenclaw, Luna naturally considered all viewpoints and none of them were easy in this situation. Of course Harry knew more-or-less what Luna did, though for him it was a much more emotional history, while for the young Lily that 'history' was as yet an unknown future. And no one wanted to know they were set to die.
Also, from appearances at this party, Lily wasn't aware she had any future with Harry's dad?
"Where's Prof-- where's Snape?" she wondered before getting to anything else.