Chingford is well away from central London where the bombs have gone off. It is east of London but not at all close to Aldgate. Chingford itself has a railway terminal but where Aldgate and Liverpool street are in zone 1 of the tube system Chingford and Epping are in zones 5 and 6 respectively. Sorry i can't post you a map but I hope this helps put your mind at rest. There will be a helpline set up some time today, if I find out details i will post and pin you.
I've been wanting to purchase a map of London, but I've put it off for years. One of those things. Today, I'll hit the book store and see if they have one. I hope I don't have to use it much in the future.
Oh, my. This is all just awful. God bless the British. They must be quite unnerved right now, but when the pedal hits the metal, they have nerves of steel.
Leni