My advice on testing would be to do as much prep now, before school starts, for the PSAT/SAT. The PSAT doesn’t matter for college admission , but she could end up a NMS, and that has real value in the admissions process. Junior year for an IBD candidate can be a slog, and to the extent that you can minimize the “piling on”, that would be great for all of you. Your daughter can take the SAT in Jan. to get a sense of she’ll do (and she can use her winter break to refresh her prep). After she gets her score, she can figure out if she wants to take a class, get a tutor, or study on her own and then retest in April. If she uses a test prep company, she may be able to take a practice ACT and see if that is better. I would recommend SAT II tests in June when the material is fresh. If she takes them in a foreign language, they’ll serve as a placement test (or better yet, exemption) if her college has a requirement. Some schools allow these to be sent in lieu of regular SAT, and it could be that this puts her in a better light. I would NOT study for them – she should be all set from her course work. You may end up with test scores you don’t need, but you won’t be scrambling either.
So now that I’ve said this, I’ll tell you that DS did not do any test prep at all until Jan. of junior year. Ho-hum PSAT score – not enough for NMS. He was an IBD candidate, and showing up at his test prep class on the weekends through the winter was about all he could put into it with all his other work. In other words, he didn’t do much work or study between classes. It did improve his score between Jan. and April, and he decided that it was high enough that he wasn’t going to take it again. He took two subject tests (as well as his SL exams). He didn’t study for either and did very well on both. At that point, he figured that while his scores weren’t as amazing as many that people have on these boards, they were fine.
Like your daughter, he plays an instrument. His orchestra director suggested that he send a tape with his application and felt that he’d be a welcome addition to any orchestra. (He had friends who were top soloists in touring youth orchestras – he was most definitely not in this category.) He decided not to do this as he felt it’d be disingenuous; his interest in pursuing this in college is slight to none. But I think that it could be helpful to your daughter if she’s interested.