I am not as advanced as your daughter, I have only jumps up to Lutz, but I can recognise myself in what you described. I am ditching my toe loop. In fact, all my other jumps including Lutz are stronger and more consistent than my toe loop.
The toe loop is the only jump I chicken out at the last minute (I do the three turn, transfer the weight to R leg and when it is time to dig, I just don't dig, I step forward and skate without the jump!) It is like if my brain decides at the exact moment that I won't do it and the body just doesn't do it. I agree that it is a very bad habit. I think in my case it may have been caused that I had a very bad technique on my old toe loop, but somehow I made the technique work for me. It was not corrected for far too long, only when I changed coaches, the new one completely reworked the technique of my toe loop, and now I have much better/cleaner toe loop, but it feels much more unstable and it is very easy to revert either to my old/wrong technique, or ditch it when I think it would go wrong.
There were several things I have tried to get out of this.
Sometimes it helped me to just practice through it and make myself do it, and again, and again. Sometimes it gave me the confidence that I knew that If I don't do it now, I would have to repeat it several times and that forced me do it.
However, sometimes the more I was trying, the worse it became. It got to the point that I would feel some sort of irrational fear when attempting the toe loop (I don't even know fear of what, because I didn't have a fall on the toe loop and I am not scared of falling. More like fear of failure?) If your daughter feels she is getting into situation like this, it may be better if she doesn't do the jump for a while (like a week or two). Then the fear gets out of her head and she can start ahead with the confidence and positive attitude.
Another thing that helped me was trying it repeatedly in a slow motion, without the speed, and only when I felt that the technique was firmly in my head I would be adding speed and again repeating it quite a few times (if it didn't work, I would again go to slow speed...)
My toe loop problems come and go. They come approximately twice or three times a year and last about two weeks, then they go and I have no problems at all with the jump for a while. I am not sure why they are coming back - whether I slightly change the technique without even realising it... My coach doesn't know why either.