We had a 24 hour layover in Oslo and stayed with Mona. I know some people feel uncomfortable staying in someone’s house and/or sharing a bathroom but forget about that if you stay with Mona.
She is a wonderful host and will provide you with suggestions (and a map) about places to see, where to eat, and the tram system. Oslo is a walking city and it’s easy to catch a tram from Mona’s place to the centre. The sculpture park and the airport express train are a short walk away too.
The room was very nice and welcoming and the bed was very comfortable. We didn’t get to use the kitchen because we weren’t there long enough but it is very well equipped. The bathroom was great and privacy was not a problem.
I highly recommend staying with Mona.