Halvorsen Family from Raade, Ostfold

Hi I am trying to find information about my Norwegian great grandmothers family. She was Jessica Dora Madeleine Halvorsen and was born in Oslo 25th Feb 1881. I know her father was called Anton Severin Halvorsen and that he was born in Raade, Ostfold about 1840. While her mother was Jensine Severine Andersdatter and was christened in Stromso, Drammen on 3rd Sep 1843 her parents are Anders Larsen and Else Pedersdatter. I think they married in 1869, they had 6 children Arthur (1866) Severinus (1873) Kristian (1878) Jessica (1881) Adele (1884) and Armand (1886) They were all born in Oslo with the exception of Severinus who was born in Bergen. Any help much appreciated can not find any records for Anders and Else wonder if they are perhaps Danish?