I agree. Her story right now is that she has cancer because she did not see a gynecologist. This is not how it works.
Seeing a gynecologist would have detected the cancer at an earlier stage, but the cancer would still be present. Instead of having the discussion right now, we would had it 2-3 years ago. Screening procedures such as Pap smears or mammograms are there to detected pre-clinical cancers when they are easier to treat and have better prognosis, they are not there to prevent cancers.
The most likely reason that she has cancer is that she is over 500 pounds, not because she did not see a gynecologist.