I think you get a say as a parent who supports your child financially and morally. I would say gently, “Never getting enough sleep is very unhealthy. You are stretching yourself too thin so you have to manage your time in a better way. You can choose what you want to cut back on, but not enough sleep and biting our heads off can’t continue. So please decide by next week. If you are unable to make a decision, we can talk through it with you.”
IMO, college shouldn’t even be in the equation for this conversation. If she brings it up, you can say “Your chances at any college will be negatively affected by not sleeping enough.”
You don’t have to take no for an answer. She lives in your home and is a minor. She seems to have plenty of independence, but seems to be unable to manage her time appropriately. Time to step in.