Hi there Susan.
How are you? I am so sorry to hear about your mother.
My mother was also diagnosed with Stage IV ovarian last October 2007 but she already had a "full hysterectomy" 9 years ago, she is now done with her 4th chemo but still her CA125 level is still at 1,995. Her doctor told us that "maybe" she has what they call the "hard-headed" tumors and will change the chemo drug on her next chemo.
Mind if I suggest you to go to the website of Memorial Sloan-Kettering Cancer Center which is in New York City. I heard that it's one of the best hospitals, you could contact them for the evaluation of your mother's case through fax.
Take care & God bless.
Pie