well if it was a boy i guess they'd call him Sirius Neville coz they named one of their children Luna, so why not neville too? it'd also be in memory of haryy's godfather. if it was a girl she could be called Iris Molly coz they used a lot flowers' names like Lilly, Rose and petunia and the seconde name is Jinny's mother.
Good question. ~:) Hmmmm, I always thought that maybe Ginny would want to name the child after someone she held close to her if they were to have another child. So, if it wasn't Fred, then maybe they would name the baby after Remus, Sirius of maybe Molly, after her mum. :)