Finding the apartment was not very difficult and she was very responsive to messages. The location of the home is about 10+ minutes from the Metro station which will take you to the city center in 3-4 stops, so it is not necessarily close to all the sights but it shouldn't be too inconvenient especially if you are staying for a longer period of time. Make sure you get a Metro day pass (~4.50 euros) because it is not very walkable to any of the sights. I might add that the area of the apartment is very residential and was perhaps a bit questionable during late night/early morning hours, so be careful!
Otherwise, Ornella's place was clean, comfortable, and affordable! No A/C (only a ceiling fan, which worked fine) but had plenty of other amenities. We met Ornella, her daughter, her daughter's boyfriend, and the family dog- they were all very nice and friendly! I would recommend this place.