Sounds like a round peg in a square hole. Hers is not an uncommon experience. Where I went to college, it was common to see engineers switching to other majors. Not because of the rigor but because they went into it for the wrong reasons. One of the purposes of college is to find out who you are. Sometimes that happens by finding out who you are not. She’s there. That’s an accomplishment.
Have the courses sh’s taken to explore other options led to a discovery of new interests? Anything from her hobbies that suggests her more genuine interests? Knowing that she’s an ISFP, you can generate a whole list of typical career interests for this type. Has anyone had her look over such a list with her?
I agree with your earlier point that it’s far better to find out now. There’s no point in having her finish the engineering program because she’s not going to use it. If she can’t decide on a new major, then she should take a semester off to figure things out - perhaps with the help of a career counselor.