- him being extremely overprotective of you

-like, if somebody even looked at you the wrong way, much less touch you, he'd kill them.

- basically being the only father figure in your life, doing stuff like taking care of you, buying you essentials, etc...

- also being your best friend

- him letting you know that you can tell him anything and that he would not judge you because he loves you and you are his baby sister

- him teaching you how to use your powers when you're really young

- Sam, Dean, Bobby, and Castiel all being very fond of you and most likely even more overprotective over you than Jack.

-Dean teaches you how to fight when you're around the age of 9-10

- then you get into a fight at school

- and Dean says " that's my girl "

- and Jack's a little mad, but he's proud of you for sticking up for yourself