I really wanted to be clear about Lily's youth - she's closer to Harry's age here than to Severus's. Until I started writing, I didn't realize how many issues I had with her - unresolved questions, a sense of curiosity, a desire to have her be worthy of Severus's incredible fidelity. Not because she needed to be a paragon - he certainly wasn't - but for the very reason that he was such an oddball and a neurotic, high-strung loner. If I was going to believe in their friendship, his sacrifice, and her ultimate generosity - if I truly intended to let her reconcile his darkness and their past with her love for her son, then I needed to make her a lot more interesting than she was in canon. She had to do more than just haunt them. She needed to stop hating Severus, even needed to fall in love with him a bit so that she could believe in him as an object of desire, and by that act release both Severus and Harry into a shared future.
I'm so glad that you enjoyed this and found it beautiful. I try not to be compulsive about it, but beauty is the specter I chase after in all my writing.