I stayed at Maites for two month during my internship.
She is partly in the flat, partly at her boyfriends house. But always reachable and very helpful.
The flat is quite big and well equipped with a nice quiet back yard. The location is also pretty good as public transportation is just near by and it is not far away from the city center. There are also Several supermarket and late night shops just 5 minutes away.
One contra aspect is that one room is directly to the street, so it is quite loud and you cannot open the roller shutter without being seen from the people passing by as the flat is in the ground floor. Another issue is the mold in the bathroom.
Summed up Maite and her boyfriend are great host and it is definitely a good place to stay in Berlin.