Where did Ты heard this?

In the epilogue it was сказал(-а) that Harry and Ginny are merried and they have 3 kids: Albus,Lily and James,that Ron and Hermione are merried and they have 2 kids: Rose and Hugo,and that Draco has son named Scorpious.It's also mentioned that Neville is working in Hogwarts as Herbology teacher and that Tonks's and Lupin's son Tedd is a boyfriend to Victoire,Bill's and Fleur's daughter.But were was сказал(-а) what happend to Luna,other Weasleys,where do Harry,Hermione,Ron and Ginny work,and what are the middle names Lily Jr. and James Jr.I mean,I read a book at least 10 times and I haven't seen these stuff there.But when I was online I saw that Percey has merried Audrey and they have daughters Molly and Lucy,that George merried Angelina and they have kids named Фред and Roxanne,that Bill and Fleur have 2 kids еще named Dominique and Louis and so forth.I also read that Hermione is working at Ministry of magic,that Ginny became a Quidich player,that Neville merried Hannah Abott,that Lily's middle name is Luna and Jame's is Sirius...So I was wondering did Ты heard about what happend to the other characters?Is it just a fanfiction that became Популярное или did J.K Rowling realy wrote it on her website или in some short book maybe?I'm just asking this cause I'm huge HP Фан since I was 4 years old and this is the only thing I don't understand about it.