If it was my kid who thought they might go a BME route, I would have a pleasant conversation. Not at all accusatory, but problem solving. Piano ability (even simply gaining enough skill to pass piano proficiency requirements) could end up being important to her and now, rather later in college, is a good time to develop basic skills. Remind her that you want to help her keep options open for the future.
It also sounds to me like there might be a problem with either the teacher, or the teacher’s approach to your D. Try asking your D about the lessons - does the teacher primarily take on young beginners, not older students like your D who might need a different approach or, other end of the spectrum, is the material too challenging so she is discouraged? Does your D understand that two more years of lessons and practice now could be a big help in making decisions about college major? If she can agree to commit to continuing the lessons and practice, she may be building opportunities.
Considering the teacher - with an older, less advanced player who might be interested in BME, I’d look for a teacher who has the ability to go beyond moving through a method book. For instance, your D should be studying things like scales and arpeggios (both for technique and for passing proficiency exams), easier accompaniments including hymns and chorales, sight reading, basic chording patterns so she can put an simple improvised accompaniment with a melody and, of course, piano literature appropriate for her stage of development. Maybe your D is already doing this, but if the teacher is unaware of your D’s interests, perhaps it would be helpful to have a conversation with the teacher about her ultimate goals.
I don’t think you are helicoptering at all. Your D’s piano skill, given her possible professional interests, is a valid parental concern. You want the best background for her, but this is a concern that a young person might not fully understand. Quite frankly (this from a musician and parent who raised kids that turned out to be music professionals) practice is generally not fun, especially if you feel you aren’t making progress. Your D may just be stuck in this trap - sadly, we don’t often see skill developing week to week. It usually takes weeks (or months) of practice till - Bang - we’ve hit a new ability level. You can google “plateau”, “music learning”, "“music practice progress” if interested and see if any of this info fits the situation.
Another thought, does she currently have a choir director that she could discuss piano skills with? It might be helpful to hear what the professionals in her life think she needs or doesn’t need to pursue her goals.