Gordon's daughter was a young girl when Two-Face kidnapped her mother, younger brother, and herself.
In The Dark Knight Rises, her mother divorced her father and took her and her younger brother away from Gotham City to Cleveland. Nothing more is heard from any of them.
Behind the scenes
This character is never named, but it can be assumed that this is the Nolan version of Barbara Gordon II. If so, this version of the character never became Batgirl or Oracle.