Isabella's house has a perfect location and she is a very nice host. You can go to Piazza Maggiore by bus 19 or 27 in 12 minutes. the bus stop (Farini) is just 50 m far from house. If you want to go to Fiera Bologna then you walk 5 minutes to Laura Bassi Station and take 39 which takes you to Aldo Moro Station in 15 mins. There is a big Conad market just 2 minutes away and 3 more small shops around. Mazzini train station is just 5 mins walk distance and it takes 9 minutes to bologna central if you take the train. You can get take any train to Florence or Venezia from this station (with train changes).
the only negatives are "no internet at home", 4th floor and no elevator, and they charge for the towels.