Anon - I'm sorry you're not getting the information that you want as that makes a difficult situation harder for the family. Doctors often take such a scientific approach to the data involved with cancer that they forget that a family member just really wants to know how their loved one is doing and if they're going to survive.
Based on what you've said you've been told, here's some information about staging. This may help you in getting the doctor to clarify exactly how he's determined the stage and grade he gave you. It's not 100% clear cut as to exactly how this pertains to your mom, but it is more information than you currently have.
Stage IIIC: The cancer is in one or both ovaries, and one or both of the following are present:
* Cancer has spread to lymph nodes (any T, N1, M0)
* Deposits of cancer larger than 2 cm (about 3/4 inch) across are seen in the abdomen (T3c, N0, M0).
(The higher the grade, the more likely it is that the cancer will spread.)
Grade 1: Well differentiated -- looks similar to normal ovarian tissue.
Grade 2: Not as well differentiated -- looks less like ovarian tissue.
Grade 3: Poorly differentiated – does not look like ovarian tissue.
You can find more information about staging and grades here: http://www.cancer.org/Cancer/OvarianCancer/DetailedGuide/ovarian-cancer-staging
Your mom is going to need a lot of support in the weeks ahead. You can learn more about ovarian cancer from the articles and support organizations listed above. You will also find articles in our Cancer Community about dealing with the effects for chemotherapy and other treatments. This may sound strange right now, but please also think about how to take care of yourself so you stay strong and healthy as you go through this with your mom. A cancer diagnosis can be utterly overwhelming for caregivers, as well as patients, and it helps to recognize this ahead of time and try to build in some breaks from dealing with cancer 24/7 so it doesn't consume you and deplete your energy, emotions and compassion.
I'm sure this isn't easy for you, and am glad you found EmpowHER, Let me know if you have additional questions and how we can help you.