The Marauder's Kids

What if Teddy was born in 1980 along with Harry while Hermione was born in 1979. Hermione finds out that she is adopted and is a pureblood witch and is Sirius Black's daughter. Furthermore, Teddy is her first cousin. Harry is James Potter's son and Teddy is Remus Lupin's son. They are the Marauder's kids. Disclaimer: I'm not J.K. Rowling nor am I in anyway affiliated in the films.