Hi Wendy! I wanted to ask if you've included Djurgården in Stockholm, the small island where the Vasa museum is located? You can hop a trolley car close to the central station that goes out onto Djurgården. OR rent a bike just over the bridge onto the island, which is a nice alternative. I've spent several days exploring here, it’s very green with numerous parks & a nice respite from the crowds. Depending upon interest, you can see Skansen, (17-19C houses & folklore), 2 lovely small art collections (19-20C) housed inside royal mansions, and of course the Vasa ship which is certainly the most famous attraction on Djurgården.
Personally, I love Skansen, and would put it high on the list after seeing the Vasa. You can check on the website when there’s folk music in one of the old houses.
There's a nice lunch spot at Skansen just inside the turnstile to the left in a small house. They had a wood-burning fire going in an oven that Swedes used from the 1800’s, we had hearty bowls of soup with bread & butter.
There are 2 small, quality art galleries housed in former royal mansions on Djurgården. Both can be reached by public transport: Waldemassude is closer, just a few tram stops past the Vasa Museum. It’s the former home of Prince Eugen who was himself a fine painter. The setting overlooks the waterways into Stockholm and there’s a Rodin “Thinker” sculpture in the garden. The cafe here serves good food.
Thielska Galleriet, another mansion, has some fine paintings including a study for The Scream by Edmund Munch, but it's further out on the island & needs a bus connection I seem to recall. Would love to hear about your trip & what you enjoy the most!