Nina's apartment is lovely and quaint and she is a very kind and accommodating host.
There are large windows with amazing views. The fold out couch makes for a decently comfortable sleep (fits 2 people comfortably).
The bathroom, and especially the shower, are tiny and difficult to navigate. You will inevitably bump your head on something. I did not find this quirk to be an overly negative distraction, however, for a 2 night stay.
You will have to take the stairs - and it's a brisk but not exhausting ascension.
The location is unparalleled if you want to explore the major tourist attractions in Venice.