Obef. is an abbreviation for obefintlig. They were transferred to the list of people whose official address was in the parish but whose whereabouts where unaccounted for. Possibly they didn't let the parish record keeper know that they were leaving.
Sömmerska means seamstress.
ETA: Here they are, on rows 6 and 7:
https://sok.riksarkivet.se/bildvisning/00070101_00084 Margareta is listed as a factory worker and the note says that she was married in America to painter Carl Arvid Hansson.