Nadia was the wife of Runar, the leader of the Neanderthal tribe, and the mother of the infant Roshan, whom Manny, Sid and Diego take care of throughout the film after the tribe is attacked by saber-tooth tigers.
In revenge for killing other saber-tooth tigers, Soto, the leader of a group of saber-tooth tigers, attacks the tribe in an attempt to steal Roshan for his meal. Nadia is able to rescue him just before Diego snatched him, but is cornered by Diego at the edge of a waterfall. Seeing no other options, she jumps. Injured and exhausted but alive, she swims to the river bank where she meets Manny and Sid. With her last remaining strength, Nadia nudged her son to these animals in the hopes that they could be entrusted with her son. The scene moves away from her, but returns a few seconds later showing that she was gone. She was swept away by the current, her exact fate is unknown.