We did not meet Katrin but had a very pleasant stay in her apartment. The kitchen is well equipped for self catering and if you need to buy or replace any food items you'll find two supermarkets within a 10 minute walk. Soft pillows and bed very comfortable. Shower lovely and warm. TV has all German channels only but the efficient WiFi makes up for it. Katrin was incredibly kind in letting us stay an extra day when our return flight was cancelled. In conclusion Katrin's apartment is like a home from home in Berlin.