I found a roll of gingham yellow and lace trim at the craft store. I added small yellow flowers to the sides.
I also made the window seat cushion from the same gingham trim. I just cut off the lace part. I had some very narrow lace left over from another project, which I used as a trim around the seat.
I added skinny sticks to trim around the walls where the two different wallpapers meet. I also used them as baseboards.
I touched up the outside paint. I added yellow flowers to the flower boxes and added the door knob.