We are a family of 5 and stayed at Laura's apartment for 3 days. The apartment is spotless and very well equipped with everything needed (particularly great kitchen, bathroom and laundry). It is in a modern building with plenty of light and pleasant terraces. We slept in the bedroom and the kids shared the living room which had comfortable sleeping for 3. Laura welcomed us when we arrived, gave us a useful booklet and showed us everything in the apartment.
A few things to know: there is no elevator in the building, so you should know that you will climb 4 flights of stairs (was not an issue for us... but something travellers with a lot of luggage or not able to climb stairs should be aware of). The apartment is in Oltrarno, in a residential area which is not very close to the main sights - however it has good access to public buses and Florence is a fairly compact city so a 20 min walk gets you to the main points of interests.