I was diagnosed  with stage 3C+ ovarian cancer this year. I was told I have to have 6 chemos, a debulk operation followed by another 3 chemos, leading me up to the end of this month [November].  I was told I had cancer on the ovaries and where they like tumours to be peanut size, mine were the size of oranges. I was to have a complete hysterectomy and there was cancer on my liver.  I was filling up with fluid so would need some Omentum taken away as the cancer cells splatter up the omentum which is;

Omentectomy: Surgery to remove part or all of the omentum, an large apron of fatty tissue containing veins, arteries, lymphatics. The omentum attaches to and nourishes the stomach and the entire colon.

I started the chemo in February my C125 levels being around the 2,000. I did so well that after 3 chemos I had the debulk operation. The cancer was only on my outer liver along with a load of scarred tissue from a splenectomy in 1983 [due to hodgekins disease, no scanner at my hospital then] so this was removed along with the rest. After my operation I asked how much of the omentum was taken and found it to be all of it. I was soon walking miles and then after 6 weeks riding my bike and driving. I had a further 3 chemos [one every 3 weeks finishing in early July. last blood test my C125 levels were 11 [normal is 35 I am told]. Hopefully they will stay low and I will stay as fit as I am. My days are long and although I am told I am not curable, I was also told I am not terminal. I am older than your Mum, but be guided by what treatment is offered. I think doing biopsies tells them what treatment is best for that particular person or cancer. My filling up with fluid had to be drained prior to the op. I was drained 3 times and each time lost a stone that day [the weight of the fluid, which was then sent for research]. Good luck to your Mum and hope we both continue to stay well.