Dear Chrissy,
That's great that she is still mobile. That is really important. I also believe that it is important to try to keep her weight up as much as possible. Ha! My Mom was also a superwoman in disguise. Unfortunately, from what I have read and what I experienced with my Mom, ascites is difficult to reverse/cure and is a sign of advanced disease. My Mom had fluid drained several times (once or twice from her lungs and several times from her abdomen), and yes it was several months (I don't rememer exactly how long) before she passed away. From what I remember the doctors telling me, the more you drain ascites, the more/faster it comes back - so we drained her as infrequently as possible, and only went for a draining, when the amount of liquid became too great and caused discomfort. In a quick Google search, I found:
Management of ascites due to gastrointestinal malignancy
Median survival after diagnosis of malignant ascites is in the range of 1 to 4 months.
But if Googling stuff gets you down, then don't, and I'm sorry. And this is only one article.
Try to catch the doctor in private, or call him on the phone. If you ask your Mom everything that the doctor said, would she tell you? I know that I wanted to know EVERYTHING.
Prayers for your Mom. Take one day at a time, don't lose hope, but cherish every day, just like everyone should.
Punky