When visiting Denmark, you should get familiar with the term hygge, which denotes coziness, and comfort.
Marie's place is very hyggelige, a great place to stay in Copenhagen. It is in a wonderful Norrebro location, close to transit and great restaurants. Around the corner from Bæst, one of the best restaurants in town (since Noma is not in my budget.) The neighborhood is very quiet and comfortable with many families.
We found it easy to walk nearly everywhere we wanted to go, but I understand renting a bicycle is very easy.
The apartment itself is very cozy, and decorated in a cute and retro style. It is on the ground floor, so you do not need to haul your luggage up the stairs. We found everything we needed to cook and eat. There are windows on to the street in the front and in the back it opens to the internal courtyard where people have dinner on warm days and children play. You will really get a taste of what life is like in Copenhagen! I highly recommend it.