Slytherin and Sirius Black

[tobyreiner]

No: HPFGUIDX 82186

Sherry:

> Both Harry's Mother and Father were magic.  If they were not they 
> would not have both been at Hogwarts.  


Of course, but it may have been that they were the only magical ones 
in their families. 

But if it's the Evanses who are the magical ones, why did Petunia 
only try to deny Lily's existence and not her parents and other 
siblings?