My girlfriend and I were also new using Airbnb and staying with Eileen has been the best experience to start with! Our stay at Eileen's place was perfect. It is placed in a very nice neighborhood and very close to everything, with many bus/tube lines around to get you wherever you want to.
She was very welcoming and warm and it felt like home since the first minute. She also gives very good recommendations on the best places to eat and go around :)
If you are looking for a nice and welcoming place to spend some days in London, Eileen's is your best choice! We will try to go again when we come back to London, that is for sure!