Ava Ferin

Ava Ferin was Jay's older sister and a Navy Captain.

Description
According to Captain Lizzie, Ava looked strikingly similar to her sister, Jay. Other than that, her appearance is unknown.

History
Ava's history is largely unknown. She was a highly respected Navy captain,

Jay Ferin
In Jay's recounts of Ava, they appeared quite close. Jay holds a clear respect and fondness for her sister, as seen by her keeping her sibling's medal on hand at all times. Jay joined the Riptide Pirates to both act as a spy for the navy, and further investigate the cause of her sister's death.

Jayson Ferin
Jayson and Ava's relationship is largely unknown. It can be inferred that had a respect for her and possibly was proud as she took on a role as a Navy captain.

Elizabeth Lafayette
In episode #57, Lizzie admits to Jay that on Joaldo she mistook her for Ava, and that is the reason she threatened her. While nothing has been confirmed as of yet, the two may have met on a previous occasion, or Lizzie may simply know her from her prominence as a Navy captain.

Trivia

 * Her name is indeed spelled Ava, rather than Ayva as many fans have thought.