Ellie is never in any real danger when sneaking past enemies in The Last of Us. The player character of Joel is charged with her protection- but her invulnerability makes this a moot point outside of some environmental puzzles. This shifts the understanding of what Ellie is to the player. Rather than a protector and the protected the relationship between the player and her is one of partners. They both need each other, but this doesn’t manifest itself in negatives (using first aid packs when Ellie’s hurt, extracting her from crowds of zombies, etc.) but in positives (assistance in combat, identifying unseen enemies from a distance, etc.).