Just as arranged, our host greeted us at the front door. The apartment is on the first floor (15 or so easy steps) and was just as advertised - clean and well-stocked for a short or lengthy stay (we stayed for a month). It is a very good size, especially for two. Although the twin beds were small (typically European), they were comfortable and the bedroom is at the back of the unit so very little of the street noises could be heard. We did not make use of the pull-out sofa, so I can't comment on that. The kitchen has everything you would need to prepare a meal - and a bonus - a decent sized refrigerator with a separate freezer compartment.
But the very best thing about this apartment is its location. It is literally less than a 10 minute walk to the Duomo in one direction, or to Santa Croce in the other. The local Sant'Ambrogio market (outdoor fruit and vegetable stalls and indoor meat, cheese, pasta etc. kiosks) is about a 5 minute walk away and it has everything you would need to prepare a meal (or you can pick up already prepared food). The local supermarket (Conad) is around the corner and it could compete with any North American supermarket. Restaurants are practically on every corner and all are quite good.
I know you will enjoy your stay at Stefania's apartment.