One thing is sure, she's not sensing. But she's probably less intuitive than I.She's much more down-to-earth than I. But she's very much NT.
No she doesn't get upset when things don't get according to her plans. She's a very calm and "zen" person.
But I think her complicated personal history explains her cool -> mother's depression and suicides when she was a little child. She learned to separate things in her mind. She went to school on a very cool way, very detached way, even though she saw her mom trying to suicide when she left home and even though she wasn't sure her mom would be alive when she gets back (but she came very early to a point where she thoughts that the death of her mom would make her life easier). She then worked at school as if nothing happened and was one of the best student in her class. Today she still wonders how she could behave like this. I think it just had to do with a defense survival behavior. Maybe that's one reason why she's still very calm today. She went through so many things.
We get extraordinarly well along. That's why I first tought she was INTP. We're like the same person except I am more active, quickier, more spontaneous, less organized, more messy, and I am much more a people-person than her. Other than that we have the same opinion on everything. This also happens with an other INTJ female friend.
Maybe she's more attracted to "bad boys" or artsy types than I also. She's a bit perfectionnist also.