Pedersdatter / Pedersdotter / Pedersdóttir means the daughter of Peder.
It is not a surname, - it is a patronymic name meaning "daughter of *", and it is very unlikely that people registered with this surname is related and when comparing profiles make sure that the mother and spouses name also match
Variants: Icelandic -dóttir, Swedish and Norwegian -dotter, Danish and Norwegian -datter.
This naming tradition was common in the Nordic counties before 1900 and are still in use in Iceland ("dóttir").