The Last Of Us 2: 11 Perfect Theories That'll Blow Your Mind

So far, players know that Ellie's mother died a few days after giving birth to her, and it's assumed that it was due to complications with the delivery, but it could have been at the hands of the cult members.

Knowing they were on her trail, it's been argued that instead of dying a peaceful death, Anna actually gave herself up to the cult before putting Ellie in Marlene's care.

Whether she definitely got herself killed or just faked her death, with the group finally thinking that they had taken their revenge, Ellie's existence could remain a mystery, with Anna's sacrifice allowing her daughter to live a life without having to constantly look over her shoulder.

Likewise, it could also explain why Ellie was always moved around in the first game. Everyone assumed it was because Marlene couldn't take her into the Fireflies herself, but it could have been an extra measure to make sure the cult never caught wind of her existence.