Genna

Genna  is a character in the third season. She is a prostitute in the King's Landing brothel owned by Petyr "Littlefinger" Baelish.

Season 3
Genna is one of the three prostitutes hired by Tyrion Lannister to service Podrick Payne as a reward for saving his life in the Battle of the Blackwater.

In the books
In the A Song of Ice and Fire novels, there is no prostitute character named "Genna". "Genna" is actually a fairly common name in the Seven Kingdoms: Tywin Lannister's own sister is named Genna, though her full name is now "Genna Frey" as she married into House Frey.