ASOIAF / Game of Thrones (SPOILERS INSIDE)

[Sirken]

some Sarella theories you say,

It is widely believed that Sarella Sand is in disguise in Oldtown as the novice Alleras, studying for a maester's chain. The name Alleras is Sarella backwards, and Alleras ("the Sphinx") bears a resemblance to Oberyn Martell. Furthermore, disguising herself as a man to learn the secrets of the maesters would be in keeping with what is known of Sarella's character.

Supporting Evidence

• Alleras is Sarella spelled backwards.
  
• Both claim to have a Summer Island trader for a mother.
  
• Both claim to have a Dornishman for a father.
  
• Alleras has similar features to Oberyn Martell (black hair in a widow's peak, black eyes).
  
• Alleras says:"I am no lord's son."
  
• It is stated that Sarella loves Oldtown.
  
• Sarella has a reputation for insatiable curiosity and "pushing in where she [didn’t] belong".
  
• Alleras' remarkable skill with a bow is consistent the knowledge that Oberyn trained all of his daughters with weapons.
  
• When Doran Martell rounds up the Sand Snakes to keep them from pursuing revenge for their father, Sarella is already out of Doran's sphere of influence and he does not send men to pursue her.
  
• Samwell Tarly was told by Maester Aemon that "The Sphinx is the riddle, not the riddler."
  
• Alleras is described as a slim, slight, comely youth with slim arms and shoulders, which is how a woman disguised as a young man would appear.