We had a great time in Copenhagen! Nina has a very nice and clean apartment at a great location (very quiet, yet close to the heart of Nørrebro, +-10 minute walk). It's easiest to go to the city center by bus (otherwise it's a 20' walk), but given that the Danish public transport is well organised and frequent (even at night!), this couldn't be any easier. Nina is an excellent host, make sure to ask her some suggestions for nice areas or bars (or whatever you're looking for during your trip). We really enjoyed staying at Nina's place, and would definitely recommend it!