Pray

I know it sound silly, but I believe that anything can be done through prayer. But when you pray you need to have the faith that God can do anything. You cant have that attitude "God if you could" but you need the attitude "God I know you can and I thank you" In Matthew 7:7-8 Jesus says " Ask, and it will be given to you; seek, and you will find; Knock, and it will be opened to you. For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened." And don't just pray yourself, ask the family to pray with you, including your daughter. I don't know if you go to church, but if you do ask your pastor for advice and ask the church to pray for your family. And when your daughter is ready, ask if she would go up to the alter for prayer. But as I have said earlier, everybody must have the faith that she will change.
Along with prayer, show her love. I also believe that love can heal all wounds. For example, when she is yelling at you and you really want to yell back, dont. Instead, when the both of you have cooled down, talk with her. Your children sound very smart, and she will like being spoken to instead of yelled at. When you do speak to her, retain your athority, but dont talk down on her, I have a feeling she wouldn't respond well to that.
Also, when she is acting in a negative way, dont send her off alone. Instead, keep her around the family. Let her know that no matter what is going on in school, her family loves her and wants to be with her. And when children say things about suicide, they want attention. Maybe you and her could set up a date for the two of you to do something alone. Like go on a walk, to the park, to a movie, to get food, or even the grocery store. Spend time with her alone, and when your alone, dont bring up her negative behavior. Let her start all the conversations and listen and respond to her questions. Your other children may get jelous, but you can do the same with them or explain to them the situation. All in all, children, especially yours, are smarter than we think, and they usually understand most if not all of what we're saying.
Also, a good spiritual base is a good start. Not religion, were there are rules, but spriritul. If you have a strong walk with God, share it with your children, so they can follow after your example. Above all, dont give up. Giving up is the worst thing you can do, it lets your children know that if things are hard, then they can give up too. And if you give up on a child, they think that you dont love them so they will continue to do the same thing to get more attention. Remember, God does things on his own time, it may seem not fast enough for us, but keep the faith and it will pull through. My pastor once said " Rough times are like slow turning ships, it may take miles for the ship to turn but it will get there."
I hope that may advice will help and I will keep your family in my prayers.
If you need anymore advice, or someone to talk to, please dont hesitate to get a hold of me, I am more than happy to help and will do all I can.
Love Natasha Johnson