I can fully recommend staying at Maria's place, but with one advise: that's an apartment for those, who read carefully the conditions and agree with them. Maria is a nice, hospitable host and an interesting interlocutor with large knowledge about London, but she could be a bit strict with rules in the house as well. That's a good option for quiet and calm guests who like tidiness. Great localization for researchers who are going to spend some time in the British Library. Flat is clean, room a bit cluttered, but cozy. I am happy with that choice, but it is definitely not for everyone. And that's OK.