Staying at Sarah's place was an amazing experience! She was super nice and helpful, she clarified all the doubts that we had and even recommended places to buy good food and places to visit. She also gave us a set of keys so we didn't have any problem getting in and out of the house at any time.
On our last night we realized that there was a problem with our flight and Sarah adjusted both her personal schedules and those of other guests so that we could stay the extra day, we were extremely nervous about the whole problem with the airline but Sarah was able to help us and relax.
As for Sarah's apartment, it is on the second floor with a very short staircase, but the great thing is that she has an elevator for the days that you are too tired for the stairs hahaha. On both corners of the block, you can find small "Deli" shops where you can buy a quick breakfast or lunch, which is very convenient and cheap. The subway station is about 5 minutes walk, the centre of NYC is about 30 minutes by subway. Near the metro station, you can find several food outlets, pharmacies, electronics stores, etc.
The neighbourhood is very quiet, we would walk back very late at night and nothing ever happened to us.
Sarah's apartment is very clean and comfortable, I would totally stay at her place again if I went back to NYC.