This question is still unanswered after 2 1/2 years , the person who posted it is no longer active on wikitree, and the profiles in question are orphaned, so it may be pointless to answer it now, but on the other hand, if someone ever does return to this profile and sees the question, an answer might help avoid confusion, so here goes. I believe that the questioner has simply confused the marriage sponsors named in the record as parents to the bride and/or groom. This marriage record does not suggest that the bride's mother has remarried to a man named Knud. The bride's father is listed simply as Ole, and the groom's father as Peder. The Knud Rolstad listed is in the column labeled "Forlovernes Navne og Opholdsted", i.e. sponsor's names and residence.