I loved the apartment - if you are looking for a Scandinavian vibe, this is a great choice. It was cute & clean. You feel that Kristine is taking care of the place and cares about you feeling well there :)
Osterbro (the district) is very safe - mainly for families with kids. Highly recommended for girls' trips - both if you plan to travel with your friends as well as alone.
Honestly, I can't wait to come back to Copenhagen and will surely look if Kristine's apartment is available. :)