Grey Mourner

The Grey Mourner is found in the East area of the Resting Grounds, behind breakable walls. Requires Desolate Dive or Descending Dark to reach.

When spoken to, the Grey Mourner talks about her dead lover, the daughter of the Traitors, and requests The Knight to take a Delicate Flower to her grave, located in the Queen's Gardens. This flower will break if the Knight uses Fast Travel, teleports with the Dreamgate, or takes damage.

Successfully completing this quest yields a Mask Shard.

The Grey Mourner is heavily implied to be Ze’mer, one of the Five Great Knights. She has a large nail in her home, and comments about serving under the Pale King when she is visited after the King's Brand has been obtained. Her silhouette is visible during White Defender’s fight, which takes place in a memory of Ogrim of his time in the Pale Court. Ogrim also makes a dung statue in her likeness, along with statues of the other Great Knights.

Location
The Grey Mourner is found residing in a house in a secret area in the east of the Resting Grounds.

Trivia

 * The Grey Mourner is a backer NPC created by Xun Zhao, confirmed by Team Cherry in a Reddit comment.

Серая плакальщица