Glad you're enjoying the game. The upstairs puzzle has a note with hints like the others, but it's pretty complicated so if you just want the full solution it's as follows:
You need interact with objects to pull their cords in a certain order, indicated by what's on the bedroom wall. Check the flower pot, the book on the table, the lady's dress, the sacks, then the man's coat. The objects are all in the bedroom except for the sacks, which are in the hall outside.
When you check the last object, the top drawer in the bedroom opens, which contains doll parts. There's a doll manual in the hall bookshelf with hints on which parts to use, the correct combination being green eye, pale arm, and heels. This gives you a key to open the bottom drawer, putting out the fireplace and letting you escape.
Thanks for playing!