Hope you've found more on the Fagerlands'. My family married and moved to the Fagerland Farm about one generation after your Gunhilda. They are indeed from the Valestrand parish BUT, that area was probably not called Valestrand around the time you are trying to find Gunhilda.
Check the IGA in the Mormon Family History Library - they'll explain what are you should be looking for based on your time factor. I'm sorry I don't go back far enough with your family name.