I was 14 years old when I was diagnosed with cysts in my ovaries. Unfortunately, I was also suffering from severe depression at the time, and I was in such a dark place mentally that I barely noticed the pain. When I finally realized that something was wrong, I started to go to doctors for help. I was misdiagnosed because of my age, and it took several months to get real help. I was told that in my right ovary, I had a tumor that was the size of a grapefruit and in my left ovary, I had two tumors that were about the size of golf balls each. I thanked god that they weren't cancerous. Many people are told that their cysts will go away on their own, and they will. Many mothers are hesitant to put their daughters on birth control because they may be young. I can understand this, but also, please understand that birth control has really advanced from the hormone crazy drugs that you may remember from your own youth. If a doctor recommends birth control, I would really hope you consider it, because it can help regulate cysts and prevent them from appearing again.
I went into emergency surgery. I was blessed with an excellent doctor, who managed to salvage almost all of my ovaries. Small cysts can be removed (if necessary) lapriscopically, and the patient can be released same day with tiny little incisions. It was necessary for me to be cut open with an incision that stretched from one hip to the other, and was in the hospital for what felt like forever. It wasn't an easy surgery to recover from, but now, I am 18, have been on a birth control regiment ever since, and receive regular checks from my gynecologist. I have not had trouble with cysts since because of the birth control. (I am also on medication for my depression, and am doing much much better)
Its never a fun thing to go to the doctor and learn that you're suffering from something that will affect the rest of your life, but I'm fine now. My friends were all very mature and compassionate about the stuff I dealt with, and I actually faced it with a good attitude and came out just fine. I even have a matching scar with my mother, who had me by Cesarean Section :)
I hope my story is helpful.
Listen to and trust your doctors, be hopeful, and pay attention to what your body is trying to tell you. Try not to be too scared, because modern medicine is really amazing.
Does she menstruate yet? Young girls have a higher chance of having cysts resolve naturally through menstruation. A short run on BC pills is one remedy to cure a hormonal imbalance which is often the cause...if the problem needs a a bit more help. Surgery is the next step. If they say the cyst is complex, solid, irregular and/or dermoid...then surgery is a likely solution. Cysts that are mainly fluid filled are the best candidates for waiting/watching...or BC/hormone treatment.
Reasons behind the pain? Pressure placed on other body parts by the cyst. Worse reasons...rupture of the cyst...will hurt for days or even weeks while it heals...and could result in a pelvic infection.
There is an even worse cause behind the pain, and that is if the cyst causes the fallopian tubes to get twisted...choking off blood supply and causing cells to die. That would be a serious medical emergency requiring immediate surgery. If she is screaming in pain and no medicine is able to bring relief of symptoms..this emergency may be occurring.