I did not meet Marta, but her friend Clara was very helpful. My brother sprained an ankle on the trip and she was kind enough to get us some medicine and bandages. So, all in all very nice person. Marta also asked via whatsapp if all was good and was swift to answer if we had any questions.
The house was located on the Lido island, which has good connectivity to St Marco's and the Airport Marco polo. The island Lido is very beautiful and one can easily spend a day or two to relax on Lido.
The house in particular was very cutely done, though the house was a lil bit old, she made it cute with nice writings and pictures on the wall.
I would recommend you to stay at her apartment since I could find nothing bad to say about the apartment and you would have a pleasant time. :)