How does Petunia know about Dementors?

[a_b_desert_king]

No: HPFGUIDX 97107

<amlesis at y...> wrote:
> 
> I was wondering how Petunia knows about Dementors and the prison 
Azkaban. After the attack on Harry and Dudley in OoP she said 
something like, I heard the boy telling her about Dementors guarding 
the prisoners in Azkaban. Harry jumps to the conclusion that Petunia 
means James telling Lilly. Well, I don't think this is correct...
<snip>

Heather now:

Interestingly, even the first time I read OotP I did not take "that 
boy" to be James.  I envisioned Lily, James and Sirius sitting in 
Lily's bedroom (with the door cracked open for decency's sake - 
right parents?) chatting away and Petunia eavesdropping in the 
hallway.  In that mental picture "that boy" was Sirius talking and 
trying to impress Lily in front of James.  Of course, this was 
before we had canon to tell us that Lily didn't like James until 7th 
year....

But even now I don't believe "that boy" was James as so many were 
led to believe.  The more theories I hear about SS and Lily being 
somehow related, the more I wonder if "that boy" was SS - maybe the 
summer before school trying to scare Lily much like Fred & George 
telling Ron scary stuff before he went to Hogwarts.  Just my 
thoughts.

Heather - who's sure we will find out more about Petunia and Lily's 
relationship in book 6.  It's just really hard waiting....