We stayed two nights at Gianna's flat. It has been completely remodeled and everything is new. I believe there is another apartment (next door) that is also available on AirBnB (similar configuration/furnishings) which might be useful for families traveling together.
Location was good - close to St Mark's square without being loud or overrun with tourists. The apartment was well equipped with supplies. Beds were comfortable. Shower had good water pressure.
The only improvements that I could suggest would be around check-in:
1) The instructions are to meet at the San Zaccaria vaporetto stop - but there are 6 different parts to San Zaccaria (A-F). Be sure to ask which dock to meet at. (We went to F; Francesca, who walked us to the apartment and let us in, was at A)
2) Tourist/visitor tax is collected at check-in and is expected to be paid in cash. €4 per person per day when we were there, but the amount varies based on time of year. We weren't told about this in advance and thus didn't have enough money with us. Gianna was flexible about this - which was nice - but it wasn't the ideal start to the stay.
Overall, this is a nearly new flat in a nice area of Venice. Highly recommended!