I very much enjoyed the stay at Alexandra's house during some of the warmest weather I have ever experienced in my life ;-) (it was 41 degrees throughout two days). The room has a ventilator and a mosquito trap :D Her family were friendly and helpful and I felt comfortable and safe during all times.
Alexandra's home is in one of the nicest areas of Florence, not the touristic and noisy parts of town and therefore very quiet at night. It is a bit to walk until her place (15 mins from the city center), but you can already experience quite a few bits of Florence (there is one big park 3 mins away from her place, that is worth visiting).
If I need an AirBnB again in Florence, I would certainly try at Alexandra's again. In the meantime, all the best to you Alexandra (including Emma and Simone)!