I attached a record to Olsten Carlsson ML51-H57. This attached his wife and children. My problem is - this is Sweden - do all the children take his last name? I have noticed they frequently do Karlsdotter Karlsson etc.
You have actually asked kind of a complex question question. It was right around 1900 that patronymics were being replaced with fixed surnames.
Osten's first child Karl was born in 1885 so was most likely Karl Ostensson when he was born. The last child, Göran Birget, may have been an Ostensson, but since he was born in 1903, he may have been Göran Birget Carlsson if that is what the family adopted as their non-patronymic last name. Or they may have adopted something else altogether.
Just keep in mind as you search for records after 1900 that you will have to keep an open mind as to what last name you might find.
Personally, I would probably put Ostensson, or more likely Östensson as the last name for all the boys and Östensdotter for all the girls on the assumption that most people relinquished patronymics slowly. Later when you find records from the early to mid-1900s and learn what the family members were using then, you can add as many alternate names under Other Information as you need to cover all their last names.
Thank you! I finally understand!