Family ring (quest item)
There is a "desperate merchant" on the Dike after Chapter III has begun. Talk to him and he will ask you to retrieve a Family Ring. You can find the ring on a dead body in the swamp, directly behind the shrine of Melitele (to the northwest) on a little island. Return with the ring, and you get 100 for your trouble.
Family ring (con artist)
This family ring which the Con artist gets Geralt to retrieve from the crypt in the sewers in Finders Keepers is also labelled "Family ring", but it's not a true quest item as it does not go into the quest items pocket.