Petunia a witch?

[Tonks]

No: HPFGUIDX 131407

I have been thinking about Petunia too. She could be a witch who chose 
to live as a Muggle, as I have suggested before. She could be a latent 
witch, but I am not so sure about that.

Maybe the only suprise is going to be that she has been intouch with DD 
all of this time behind Vernon's back. She is a Muggle who knows that 
the WW exist and maybe knows some of the people there, but does not 
associate with them. Except there is that Owl the same color as the 
Longbottom's owl. There are other little indications that she has 
gotten more than one letter from DD. I think that JKR has hinted that 
herself.

Clearly Petunia knows that magic exist, and so does Vernon. They want 
nothing to do with it, probably because they have seen the danger in it.

I think the *secret* is that Petunia, fully Muggle, is going to let out 
that she has in fact been in contact with DD more often than Vernon 
knows.  In addition, she could under stress to save her family come up 
with enough magic to do the *trick*. If this happens it will be to show 
us that to some extent the power of magic is in us all.  And finally, 
maybe she is going to just going to bake Harry a birthday cake... about 
time. 

Tonks_op