D.N.
I had one at Christmas-started that night. It finally went away after putting cold clothes on it. I asked the doc at my daughter's appt and she said they can come from stress or bacteria in the eye-or touching something and then rubbing the eye. Similisan makes a drop for styes. It is supposed to help heal and relieve the symptoms. Also, make sure your daughter washes her hands often and does not rub her eyes.