They would probably not have sailed directly from Sweden to the US. There were regular lines from Göteborg to England and some emigrants are found in the German ports of Hamburg and Bremen. There was no mandatory registration of emigrants in Swedish ports 1861-1868.
This could be Hedvig:
Förnamn: HEDVIG SOFIA
Ålder: Kön: K
Titel/Anm: ÅLDER SAKNAS (No age stated)
Utvandrdag: 1870 05 20
Destination: NEW YORK
She sailed on the Rollo from Göteborg to Hull.