This is from the Mayo Clinic site:

Recent studies have shown that women with ovarian cancer are more likely than are other women to consistently experience the following symptoms:

• Abdominal pressure, fullness, swelling or bloating
• Urinary urgency
• Pelvic discomfort or pain

Additional signs and symptoms that women with ovarian cancer may experience include:

• Persistent indigestion, gas or nausea
• Unexplained changes in bowel habits, such as constipation
• Changes in bladder habits, including a frequent need to urinate
• Loss of appetite or quickly feeling full
• Increased abdominal girth or clothes fitting tighter around your waist
• Pain during intercourse (dyspareunia)
• A persistent lack of energy
• Low back pain
• Changes in menstruation

It worries me because these are such vague symptoms, that they could be anything.  That is why I posted about early detection.

I think the best way to prevent it, is to have your ovaries removed.  I don't know of any other thing that prevents cancer.

Ovarian cancer is a tough one.  I'm sure they can test early if someone in the family has had it before.  I think she should tell her doctor that her family member had it and there are tests that can be run.