I think (and hope) you will get the book on how to do the Gerson Therapy so you understand better how all the different things you need function in the Gerson Therapy.
The Gerson Therapy, as an example, is based on Science and testing on patients to refine the different parts of it. Work to further refine the Gerson Therapy was done over decades. Other alternative methods followed the same lengthy route.
The people working on the different methods thought out what the results would be and then observed to see what actually happened. This is what both you and your mother must do. A lot of people find themselves in dire straits such that they cannot afford the Norwalk juicer, so then search for a good, used, Norwalk juicer. If your mother doesn't feel like cooperating by saying she already has a kitchen full of blenders, juicers, and there's isn't any room for a big juicer then you have to discuss with her how relevant or not relevant each of her objections is. Get her to understand you will be following a scientific procedure, not some quacky thing where you can throw some things together using what you already have in the kitchen. If one or both of you believe you can take some things from here and there in a random fashion, you will not get a good outcome. Many things in these alternative methods are not optional, like deciding which movie you want to see.
You are talking about using the juicer you already have, or getting another one but without the press. Well, have you tested (on a cancer patient) how a 6 month or year program using the juicer without a press would affect the outcome? (Perhaps someone who has tried this with the same problem your mother has could post the result they got--if they read this.)
You are talking about the expense of a press or Norwalk in your hardship situation.
The juicing part of using food to restore your health requires enourmous amouts of vegetables/fruits to be squeezed/juiced each and every day. Why? Because when the whole health picture has deteriorated to such a point that you have cancer, your body takes and uses so little nutrition from the food you put in (the body). So, to improve, you have to put the food in many, many times throughout the day. This means, in terms of money and expense, that the more juice your juicer of choice can squeeze out, the less you pay for the vegetables you buy. If one juicer needs 10 vegetables to be juiced in order to get one 8 ounce glas of pure juice, then that juicer will cost you less at the end of 6 months than a juicer that needs to juice 30 vegetables to get one 8 ounce glass of juice to drink. The difference saved on the amount of vegetables you buy between the two juicers at the end of a year is enormous. Get the press or a used Norwalk and you will save money because you will have to buy less vegetables. One juicer costs more because it squeezes out more juice.
If you are in the UK, there is a Gerson support group there (check their web site) and they can help in locating a good, used Norwalk. Maybe you can box and store some of the regular juicers and other things at a neighbor's while you work on the cancer.
Perhaps you are asking these questions to get an overview of all the different methods so you can decide. Select one method. You cannot make up your own method as you go along and expect to get good results. Look at each method as a sort of package where each part has its own function to heal from within the body. You can add to it, but don't stray too from from the method and come up with your own. Your own method hasn't been tested on anyone. Whole lifetimes have been spent creating a method(s) that heals and does not damage the immune system. You won't be able to do this just be reading some posts and then hoping that one ingredient does not cancel out another rendering your method useless and allowing the cancer to increase.
You cannot kill too many cancer cells at once. There are many things (variables) to consider in setting up an alternative method of restoring health (from cancer). You don't want to overload the body. This would result in death. The body is finely tuned to measure everything that comes in and reacts to it on its own (time) schedule. You have to go along and work with whatever schedule it is at and change your program when the body's program (schedule) changes. (The Gerson book has a couple hundred pages on how to do this and in what order.)
Select one method you can best afford. Follow the guidelines for what to eat for that method. One of the others (post) recommended this also. You are taking on way too much, to create your own alternative method in a few days--if this was your design.
You have to come to a "meeting of the minds" with your mum. If taking 100 or more tablets or enzyme capsules each day, like I believe Kelley(?) method requires is something your mum just doesn't want to do, then get your enzymes from juicing. You have to know how these methods work so you don't double up on one thing inadvertently. Since there are not extensive comparison tests showing what happens when you take one part from this method and mix it with that part of another method, you need to select one method that you can do. It's too bad this hasn't been done, but you can succeed without it. It appears the popular government organs that test these things think its's more worthwhile to test the same chemotherapy drug over and over rather than do something like what you are proposing. They don't care because the $50,000 a year bill for using one chemotherapy drug isn't paid by them, but by the average employee when it's deducted from his paycheck through high health insurance premiums. (They change a few molecules on a drug so they can study it, and then call it "new" so people won't mind when their health insurance premium/deductions so up to pay for it.)
Getting the organic food into the cancer person's body in a form they can ABSORB is very difficult to do. Hence, the genius idea of using the juicer. Whatever alernative method you use, they all require you eat mainly vegetables, some fruits, to strengthen the immune system and restore health.
And if you can possibly work it out, get a friend to assist you one or two days a week (doing something--ie.cleaning a room, ect.) so you don't run out of energy and enable you to continue to help.