We didn't get to meet Ursula our host but she made arrangements for a neighbour to meet us which worked fine.
It is a reasonably good location in Kreuzberg, not too noisy and probably a good 20 -25 min walk to Ostbahnhotf U-Bahn station. Noise seems important in Berlin, as there is a lot of partying at night and we were immune to this. It is an interesting Turkish neighbourhood with good little restaurants only a 10-min walk away.
The apartment is very clean and cool and we would certainly stay here again.