Karen is a lovely lady and very good host.
Her flat is very well situated about 5 minutes walk from the Imperial War Museum one way, and the Elephant & Castle station & shopping centre in the other direction. Buses to the West End and City go from nearby. Public transport, or pushbike, are probably the best means of travel locally as parking is restricted in the heritage listed streets around Karen's place. There are plenty of places to eat and drink nearby at reasonable prices- the pub at the end of the road looks a bit dubious from outside but the grub, beer and welcome inside are worth venturing over the threshold for.
Thanks Karen, I really enjoyed my stay.