Marthe Pedersdatter - parentage & birthdate

I'm trying to figure out the parentage and birthdate of Marthe Pedersdtr. She married Christen Hansen June 21, 1825 in Faaberg. At that time, it appears she was living at Arlien and age 25, meaning she was born about 1800. 1865 Faaberg census records show she was 70, meaning she was born abt. 1795. 1875 Gausdal census records show she was born in 1797 in Faaberg. I have not yet been able to find her death record to see age listed. It appears she is the daughter of Peder. Is there any way to determine which year she is actually born as I would like to discover actual date and her parents names. Thank you to anyone who is able to help me out with this puzzle. -Dusty