I want to mention Molly, the ghost (who didn’t know she was a ghost) in episode 2.16 “Roadkill”. I thought that her character was interesting and she had a really unique story. That episode as a whole was so original, there hasn’t been another like it.
I also liked Layla, a woman who was hoping to be healed by the faith healer in 1.12 “Faith”. She was very caring and friendly towards Dean who was also going through illness at the time.
Marin was another one-off on my shortlist. She was a patient in Sam’s psychiatric ward when he was being haunted by hallucinations of Lucifer in 7.17 “The Born-Again Identity”. Like Layla was to Dean, Marin was also really friendly and open to Sam. Sam and Marin really understood and helped each other, which was probably the only nice part about that episode as it seemed really depressing and sad at times.
As you can see, I have many favourite one-off characters, and there are plenty to choose from because, as we all know, women don’t last very long on Supernatural. However, my all-time favourite one-off female character would be Nancy Fitzgerald.
Nancy was an amazingly beautiful girl (inside and out) who appeared in 3.12 “Jus in Bello”. She does get murdered at the end of the episode at the hands of Lilith (as I watched through my tears) but she goes through so much character development within just one episode, it’s truly inspiring writing. As she starts out she’s a timid, shy, hard-working receptionist and she stands by her Christian religion and faith which continues throughout the episode. She prays and cares for Sam and Dean when none of the other police station workers would even look at them and even when she herself was afraid of them.
Then, near the end of the episode, having been confronted with demons and having to adjust quickly to the dark truth of the world, she transforms into this brave and courageous woman who is willing to have her heart ripped out in order to complete a ritual that would kill all demons within the immediate facility, saving everyone, including strangers she had just met. She spoke up and decided that she wanted to be a hero and help save the remaining people in the station even when she was just an innocent bystander in all of it. A very brave character who I look up to and she did not deserve to die, as it completely contradicts her awesomeness.
I also think that Nancy showed viewers that you don’t have to be confident or sexy or outgoing in order to be great.