Long time since this board post, so I do not know if you are reading my reply.
I have however some information about the norwegian part of the family of Kjersti Jonasdatter Brattlia/Tangen. My greatgreatgreat grandfather Johannes Jonasen Tangen was Kjersti`s brother. I live not far from this area in Norway today. Please contact me if you like, and we can share some information.