Today I also have the notion to break up the roof into two parts so that I can more easily make a second floor window on the south wall, which will have the nicest view looking out from the playhouse. Here's my first pass at this approach.
The problem with this idea is that it will cut into the head room people will need as they climb up from the first floor to the second floor. Perhaps I will stick with the previous single roof design and put in a "dormer roof" where I want to place the second floor window on the south side. Of course I don't know how to build a dormer roof. So that's another thing I have to learn!