Nathan and Elena’s daughter in Uncharted 4 is nicknamed Cassie. Her full name is Cassandra Drake, and she appears during the game’s epilogue as the teenage daughter of Nathan Drake and Elena Fisher.
Cassie is named after Cassandra Morgan, Nathan and Samuel Drake’s mother. That family connection gives her name extra significance: Nathan’s childhood identity and his mother’s history are important threads in the series’ backstory. Cassie’s curiosity also mirrors her father’s adventurous personality.
In the epilogue, Cassie explores her parents’ house while they are away. She discovers a locked wardrobe containing photographs, relics and other evidence of Nathan and Elena’s dangerous treasure-hunting past. Once her parents realize she has found the collection, they decide she is old enough to hear the real stories behind it.
A common mix-up is treating Cassandra as a separate character from Cassie. Cassandra is her formal name, while Cassie is the familiar form used for Nathan and Elena’s daughter. She is also playable in the epilogue, voiced and motion-captured by Kaitlyn Dever.