Sorry that things are not going great. I hope this does not seem like a stupid question, but are you blending the flax oil with cottage cheese.
It might be worth combining the Budwig approach with the coffee enemas used in Gerson therapy.
Perhaps the conventional therapy is undoing what good the diet is trying to do. I am not a doctor, I can only speculate from what I have read, and what does a person do in this awful situation............we clutch at straws.
I wonder if you might be trying to hard with all the vitamins. If she is drinking freshly squeezed juices and following the Budwig diet she should not need extra vitamins..........too much of a good thing might do more harm. One of the rules of the Budwig diet is "no other fats" I think that might include no other oils apart from flax oil.
An improtant point about Juice is the way it is extracted, as many juicers destroy the all important enzymes. It might be worth looking at the way juice is extracted for Gerson therapy.
I hope things start looking up for your Mum very soon.