Thanks for your query.
You didn't mention the size of the Ovarian Cyst
and the side,whether Right or left.
Most common complication of ovarian cyst is rotation along it own axis,TORSION ,which is extremely painful condition associated with vomiting
Rupture is also a complication described in literature.
But,please consult your Gynaecologist and get Ultrasound
abdomen of your daughter immediately.
It looks like an emergency.
Please don't waste time.
I wish her speedy recovery.