it's a videogame, get over it.
You know what will happen if you're able to directly kill a kid in a video game by burning them alive or brutally beating them to death? If they put Ellie in multiplayer then the game would be taken off store shelves and anti-video game activists would use it to slaughter the gaming industry. Probably making ND go out of business. Why? Because you can kill a teenager. It's Single-Player skins.
Get over it? We'd never hear the end of it, let alone get over it.
I doubt it has anything to do with her age, its her height thats the problem, the hitbox would be smaller than the other characters meaning a big advantage when using her.
I'm pretty sure it is because of her age.
Pinning a 14 year old female down and repeatedly bashing her face in with your fists might be a bit much