I haven’t ever seen plans for the stool. I am sure it is something you could modify with a graphic, some extra lumber, and some time. I found a couple different styles here:
http://www.adirondackchairs.co.....38;Ntk=all

Good luck.

http://www.woodworkcity.com

ps: also not to push for nyws but you want find a better adirondack chair or loveseat design anywhere.

I can’t give you too much advice other than to say reduce by a factor that makes sense for the size of your daughter. There will be a lot of trial and error, but you should be able to lock on on a scale. If I were building it, I would find another child’s chair (doesn’t have to be an Adirondack) and figure out the seat height and arm height. From there, I would do the math on the ration that I would have to scale it. I would make those changes and adjust things as needed. Once you have the frame together for the second chair, you can essentially skin it with the slats.

Good luck.

PS: Try to find a book at the Library on woodworking with/for children.

Thanks
Paul