Hii!! Not weird at all omg :)
Ive watched the walking dead enough to know the entire plot of the show. So for me, writing Charlotte’s character I already had a rough draft in my head knowing where I wanted her to end up. When it came time to writing the scene’s, I had TWD episodes pulled up right beside me and I’d go back and forth between writing the dialogue and watching the show — I think a key factor is having enough similarities and differences between your writing and the show. It’s okay to switch up script or conversations to factor in that there’s another person (your character) there now too. Even changing up the way some scenes play out is perfectly okay. In short : yes, I watch the shows as Im writing. I also include my own scenes and own script to try and differ my fanfic from the show.
I hoped this helped!!! Feel free to ask any questions <3