Mari(e) Olsdatter

Marie Olsdatter Tande married John Nielsen Magelie Nov. 17, 1806 at Oyer, Oppland, Norway. At that time "Tande" appears after her name, but I don't know if she works at this place or if she was born here. John Magelie and Marie went on to have 12 children, all born at Magelie Oyer, Opp. between 1807-1835. There are no census records available during this time period for me to find out her age or birth year. I am looking for suggestions on how to find out her birthdate (since I don't know the year she was born) and her parentage. Any ideas or suggestions would be very appreciated. Thank you, Dusty