If she is in school then you have a say. Set a fair time and take the phone away from her until the morning, if she cant take responsibility and get enough sleep, thats where the parents job comes in. Its not a case of babying her, your job is to get her through school and assist where you can to remove distractions and influences.

My daughter has the same problem. The activity that they engage in (in my case TV) let them go and sleep very late or early morning and they still need to sleep the same time as with a normal pattern. It is like with students that study late and after studying has to restore to normal pattern. The teens are teaching the body a certain displaced pattern (not normal sleeping hours) until they get rid of the acivity (Phone, TV, etc). Getting them off these bad patterns could pose a difficulty as in the case of the phone, it forms teir social life as well. My other daughter would be on the phone at 2 in the morning. she outgrew that. I, unfortunately, forces my daughter to go and sleep early, but one never knows what happen after you fall asleep.

take the phone away from your daughter during school nights. Problem solved.

You have lost control. My daughter is 16 and when I say off the phone, to bed or lights out she listens. She knows it will not help to get angry, then I will just take one of these away. Kids get angry (we all did) and they get over it (we all did). Be a parent not a friend.

If you are paying for the phone (directly or indirectly), take it until she agrees to change
her ways.Remember, she is living with you. You are not living with her.
Contrary to what many people think, children (and teens are still children) need to be
kept on the rail and need to have boundaries (it is their security although they will never
acknowledge it). But if the phone and the sleeping thing are the only problems, you are
a blessed parent. Good luck.