Your daughter may be in for some serious complications. Having a mass and taking pain pills do not help at all.
Further management of her case is very important before any complications arise.
Please check with her treating doctor if her mass can be excised. It can then be sent for histopathological examination to look for malignant cells, if any.
Birth control pills may not always help in curing the disease; it only regulates the hormonal
A laparoscopic drainage
of the mass may be helpful.
You need to speak to the doctor about all these. Else, please get a second opinion