ixfj has Ti as third function and third function usually works pretty well in their 20's. i know two ixfj women, other is 22 i think other one is 27. younger one is pretty unhealthy, has mental problems, total lack of Ti and i doubt that she will develop much of Ti in the near future. older one is healthy(at least seems healthy as person can be, other than believes in imagination creatures(god) and is jealous), she has good Ti and seems almost like a T type, but what gives her away as F is that when it comes to something that goes against her values, like when a rap song says yo bitch for example, she thinks that its discriminating women and wont change her mind about it(but will listen to your arguments), no matter how good of an argument you make about it. she is clearly J type due to organizing, but isnt prejudice about everything, like some strong J people are. but shows Fe clearly.
i think when people say non-logical, they actually mean irrational and Fe + Ni combo can get bit irrational at times.