One last thought. If you really want to tie her gymnastics future to something she can control, then pick a different yardstick than scores. Maybe ask her and her coaches to evaluate her effort on a daily or weekly basis? You can ask her to work hard and train hard. You can't ask her to do better. It just doesn't work that way.
^^ I agree.
Okay, this may get long, redundant, and a bit jumbled up, but here's my thoughts:
I completely understand the idea of, why should we put all this time, money, and effort into something if you aren't going to give it 100%. I have had to have that conversation with my oldest several times (not my gymmie). No reason to spend thousands on something your DD isn't taking seriously (if she, in fact, isn't). I think the issue is in using scores to measure her effort or commitment. Is there another way you could gauge her effort, such as having the coaches evaluate her like Chocoholic mentioned? Or watching several practices over a period of time to see if she's goofing around or working hard?
Could you just approach your DD from the angle that it isn't fair to the family to commit this level of time and money to something she isn't going to give 100%? Let her know that she either needs to step up her effort during practice, work hard, and do her personal best or you're going to have to look at other options. I wouldn't make it feel like she's in trouble so much as just acknowledging what you've seen (assuming you've seen her goofing off in practice or not doing her best, etc.. - NOT scores). Talk to her about WHY she's not trying as hard as she used to. If it's just too much, offer (again) a less rigorous program as a good option to keep her in the sport while reducing the needed commitment by her.
If you're feeling like you're already beyond the evaluation stage and your DD has already shown that her heart just isn't in it anymore (after having it brought to her attention that she needed to work on her work ethic - again NOT scores). I would sit her down and let her know that she had her chance to show that she still wanted to do this, and she hasn't. Something has to change. The family can no longer commit this time and money to something she has proven she is not going to take seriously. And from there, discuss other options and/or quitting. Whatever works for your family.
I just really think you need to peel back the layers and find out WHY she is not 100% committed anymore and address that issue - whatever it is. If you're basing her apparent lack of work ethic on scores alone, I think you need to look further into it and find out if she is actually not working as hard as she used to or if she's just in a skill/form slump right now.
I think those who have taken issue with your position really are taking issue with using the scores as your measuring stick. Find out IF she's really not committed/working hard/doing her best first. Then, address WHY she's not. THEN, you can figure out where to go from there. Just leave the scores out of it! JMHO.