I definitely wouldn't use it for a British character - to be honest I would assume a character called
London was most likely American! Naming people after British towns definitely isn't a British trend.
Of the others on your list I would say most of them sound like more American names too, they are all quite uncommon over here (I'm in the UK). I do know of 2 Haydens, but they are both men!
What about
Sam,
Alex, or
Laura?