Cognitive Introvert but social extravert.

Actually I don't see any 4ish traits in her. Definitely in her tritype but I think a lot of her behaviors where cp6-like, she sees herself as a hero fighting for the underdog and rebels against the authority she believes don't protect the people. I am uncertain about the wings but leaning 6w7 because of how she's kind of a hippy and free-spirited.

Also she is definitely chaotic good over chaotic neutral, she does bad things sometimes but there is always the intent of helping others rather than herself (the floor is lava episode where she gave up the chance of winning to help abed)

I don't see any Ne...Can someone explain? I went with ISFP because it made the most sense to me but I can be swayed.

“ SPECIAL? YOU'RE NOT SPECIAL. I'M SPECIAL! I WAS BITTEN 10 MINUTES AGO with- *zombie noises*”

Say what you want about her but she was pretty funny

Ugh INFP 4s, always faking individuality
People acting solely by Fi and Ne are entitled wannabes.

"If I had no self-awareness, I think I'd know."

Shes a 4w3. This is evident in the fact that shes obsessed with having worth through achievement and always gets sad whenever she realises how little shes achieved. She has more shades of 3 than 5. Ive never seen a moment in the show when shes analytical or has a desire of understanding reality and being conceptual. She has a fear of being worthless through her lack of achievement, which makes her more 4w3 than 4w5.

her not being an ISTP like it was hinted in the pilot is my villain origin story

I've found that INFP 4s are often either super awesome or super frustrating. I know any type can be, but this combination seems especially inconsistent. I think it's because 4 is a very Fi-oriented type and INFPs lead with such strong Fi to begin with. I guess by this analysis the same could be said for ISFPs, though I see Ne-Si as being more dangerous than Se-Ni in situations like this. I'm very grateful that I'm a 9, because it's so Fe-oriented and it balances my Fi out. Even then, the Fi wins that battle more than I'd like.

I don't think Britta is an INFP - I know there are stereotypes floating around that say otherwise, but high Fi isn't generally inclined to moralise at people for the most part. It's generally pretty live-and-let-live unless a hard boundary is crossed, because it's self focused and self referencing - 'I won't do this, but you do you'. The kind of performative moralising Britta does where she tries to get everyone on board with some cause or another is 100% Fe.

I also don't see 4 at all - she's a meddler who wants people to perceive her as helpful and moral, to validate her self-image as a 'good person' - so 2w1.