Sonja has been a great host, helping with anything we needed during our stay in her flat, she also let us to checkin earlier because we arrived before our schedule. I have just kind words to describe her.
The apartment is great , it has everything you need and more, lovely decorated place and very illuminated, you will feel like home. The area is also super safe and you can walk (if you like it :) ) to any interesting spot in the city.
I would definitely stay in her place again in Berlin