From A Land Far Far Away - Skellige
Location: East of Redgill
Quest Giver: Loot Journal on corpse
Other Requirements: N/A
This quest begins by looting the Journal next to a body (pictured above) on a very small island east of Redgill in Skellige. Your first objective for this quest will be to search the sunken treasure chest mentioned in the journal which is found on the southern side of this island in the water. You'll see the mast of the boat sticking out of the water from land.
Loot the treasure chest to update the quest - it sends you to a location in Velen, a village by the name of Ursten. Assuming you fast travel here, right near the Signpost you'll find a Warrior with an exclamation point above their head (pictured below). Whether or not you speak to him changes the dialogue of the upcoming event in this quest; speaking to the Warrior means you won't be able to give the woman the documents you found.
From the town of Ursten you'll want to travel northwest up the coast - you'll find a crashed ship along the coast with the same crest painted on it as the one from Skellige. Inspecting the boat will update your quest, then you'll want to inspect the foot prints near the boat to continue with the quest.
You will follow the footprints to a Guarded Treasure location your map which is a tad bit south of a cave entrance as well as the Widows' Grotto Signpost. Here is where you will find the woman and engage her in dialogue. As aforementioned, if you spoke to the Warrior then as you approach the woman he'll be arguing with her.
If you did not speak to the Warrior you'll approach the woman by yourself and speak to her then the Warrior comes later and tells you that the woman is a criminal. You can choose to defend the woman (which means killing the Warrior) or letting him do whatever he wishes with her.
Whatever you decide, the quest will end after your conversation with the Warrior. Letting the woman live/saving her will net you a Stone Medallion, which is your reward for completing the quest. The item is basically worthless (to you) but was probably very important to her.