Basma is probably the most warm and welcoming host we've stayed with! She truly made us feel welcome in her home, complete with juice and cake when we came in. She graciously gave us a map of the city, and showed us the "must go to" places in Istanbul! Her home is about a 30-40 minute walk from the Blue Mosque/Hagia Sophia and even less to the Grand Bazaar.
Her home is very simple, but comfortable. If you choose to go there remember you are in someone's home, and not a hotel! Our only regret about our stay is that we didn't get to have more time there.