Many responses (Molly's age, Hagrid, JKR stuff, unforgivables, etc) - also, Moody's Eye

[bookworm857158367]

No: HPFGUIDX 174105

The idea of magic attracting magic is an interesting one. It would 
make sense if there are two or more magical genes that must be 
inherited to produce a witch or a wizard and it would make more 
sense if those genes came from both parents. Wizards and witches who 
marry Muggles and produce magical children are probably marrying 
people who carry magical genes themselves, even if they aren't aware 
of it and Muggle-born witches and wizards like Hermione and Lily 
Evans have probably inherited magical genes from BOTH parents that 
combine to create a fully magical child. People like Petunia and 
Hermione's parents are probably "half-magical" instead of being 
simply Muggles. They can't create magic themselves, but may have 
enough of the genes to recognize it, be attracted to it, step into 
the world and experience it. Petunia can write to Hogwarts; Dudley 
can experience the full effect of a Dementor; the Grangers can walk 
into Diagon Alley with Hermione or onto Platform 9 3/4 to see her 
off. It takes a certain amount of magic to be able to walk at a 
pillar and out onto a train platform that no Muggle should be able 
to see. Dudley Dursley's son or daughter might conceivably be at 
Hogwarts as well if he married another half-magical Muggle (as he 
very well could have) and produced a witch or a wizard. It would 
serve his parents right. 

Bookworm857158367