Supernatural Fans

Can anyone tell me what Season it is Charlie first appears in? She is awesome, but I've only ever seen random bits of her on Tumblr. :( Please help me out! :D

I am so irritated with Financial Aid at my college. I have filled out the same form 3 times now because they cannot seem to remember me already signing it for them. I may never get to register at this rate. :/ That said - I really am trying to be more Positive Minded. :) LOL!