Yay! I was going to do up a tree, but this looks much better than I could've made.
Looks right so far!
Right now we only know the ages of James and Serena. I just made Freddy and Lily pranksters instead of proper prefects, so they could be in any year after 1st really, not just 5th, 6th or 7th. Albert could be up to a year old (or he might have been walking in the first flashback).
Gosh - I can just
see Gryffindor Common Room full of redheaded Weasleys!