Blind: Supernatural

Imagine Sam and Dean's mother had not died when Sam was an infant. but instead died when Alexandria, their sister, was just 6 months old.
she was 6 years younger than Sam and 10 younger than Dean. she was born blind but John only found out when she was 3. image being a blind hunter.

Alex fights everything from witches, vampires, and Wendigo's to demons and Dean.

Will she stop the end of the world before it happens? Or will she be the cause of it?

This is not going by the show so the big happenings are way out of order meaning the apocalypse will happen after they get the bunker, the angels falling will be before the apocalypse or stuff like that.