My Daughter Has A Very Enlarged Thyroid. Her Blood Tests

My daughter has a very enlarged thyroid. Her blood tests came back normal and she is scheduled for an ultrasound tomorrow. She is almost 23 years old and is attending graduate school in another state. Her obgyn noticed this in the summer, took blood, which came back normal. My daughter felt that the swelling had dramatically increased and sought medical treatment last week. Again blood work normal.