I don't see where people are getting "N" from for her. Her lyrics are very concrete, usually using either every day dialog or fairly prosaic story telling. She doesn't really use very much abstraction or symbolism for a songwriter. I'd say she was an SFJ.
Her lyrics are very concrete, and I don't know why people think if she writes her own lyrics that would make her an N. William Wordsworth wrote beautiful poetry about nature and relationships and he was an ISFJ. I also have reason to believe Agatha Christie was ISFJ, and she's one of my favorite writers.
I'm going to say INFJ for Taylor. A lot of INFJ's can seem really open and expressive if their personality is outgoing, but on the inside is the other half of their world that other people can't even begin to see. All her song lyrics could be a reflection of how she really feels inside, as most INFJ's don't reveal their true feelings but only let people see glimpses of it through music/art that they do.
I'd say ISFJ. I agree that the way she writes comes across as very Si and Fe. And the fact the she consistantly describes herself as being self-conscious and awkward in social situations growing up leads me to lean toward I instead of E. ESFJs tend to be super sociable.
Although we're not the most artistic bunch overall, it is possible for SJs to be creative is some form or another. There are even a few SJ type 4s.
"I took one those personality tests. It came back negative." - Dan Mintz
After seeing an interview of her, I'm going to say she's an xSFJ, I'm leaning towards ESFJ but she could just be an ISFJ who's used to performing/being around people. Based on just lyrics alone I said INFJ, but seeing her interaction in an interview is something totally different.