Harry's grandparents

[scoutmom21113]

No: HPFGUIDX 71748

Something just struck me while reading a post about Petunia.  We have 
all been so curious about Harry's family.  Harry was not allowed to 
ask questions while he was growing up so he doesn't know anything 
abut his parents.  But what about his grandparents?  

Surely Petunia would have told Dudley about her parents even it was 
just to say that they died before he was born or whatever.  Harry 
would likely have overheard.  After all, Petunia admitted to having a 
sister by telling Harry that his parents had died in a car crash.  
Why would they keep quiet about Petunia's parents?

Ravenclaw Bookworm