Gudrun Hille from Mandakl

I'm looking for information on my grandmother Gudrun Hille (married Seyffarth). Her family name was once Gabrielsen, until they changed it to Hille (an island off Mandal). The family moved from Hille to Halshaug, Mandal. her father's name was Gabriel, mother was Petra. Brothers: Golman and Paul. Sisters: Henny and Alice.