Who will perform magic "late in life"? (Was: Theory on Petunia)

[Hagrid]

No: HPFGUIDX 156698

> Lynda:
> My candidate, just because everyone else is so "obvious" (Filch and 
> Mrs. Figg are squibs--Petunia's sister was a witch and her nephew is 
> a wizard--known magic users in their families) is Aunt Marge.
> 
aussie writes:
Petunia? Dudley? Figg? Filch? ... and now Marge?

What non-magical people haven't we included in that list?

- The Prime Minister of England
- Grawmp
- the pretty girl in the paper shop (near the Burrow) that thinks
George's card tricks are just like real magic
- Trelawney (has she ever done anything magical except open the Room
of Requirements?)

aussie (the unreliable plot suggester)