From A Wiki of Ice and Fire
|Alias|| Misery, the White Worm|
|Title||Mistress of whisperers|
|Book(s)|| The Rogue Prince (mentioned)|
The Princess and the Queen (mentioned)
The World of Ice and Fire (mentioned)
Mysaria was taken as a lover by Prince Daemon Targaryen in King's Landing, and she quickly became his favorite. Around 105 AC, Mysaria became pregnant with Daemon's child while living at Dragonstone. Daemon gave her a dragon egg for the child, which angered King Viserys I Targaryen. The king ordered Daemon to return the egg and send Mysaria back to Lys. The child was lost during her exile back to Lys.
Mysaria was possibly involved in the assassination of Prince Jaehaerys, a son of King Aegon II Targaryen. Daemon's go-between, a pale stranger whom he trusted, hired the assassins, Blood and Cheese. At some point Mysaria became Daemon's mistress of whisperers. Lady Mysaria gave warnings to Rhaenyra during the riot of King's Landing.