I am on Day 33 and am doing fine.
I drink 5 lemonades a day (and that is plenty for me).
I chase a 22 month old around all day; I mow our yard weekly; I climb stairs at least 6 times a day.
Every person's body and diet history is different.
Your body will tell you your progress.
If you are overweight, you can probably stay on the Master-Cleanse longer than someone underweight.
If you have eaten a bunch of junk food for a majority of your life, you probably have more toxins to get out than a organic food eater.
Your tongue turning from white and coated to pink and clean is another good sign you are done.
And don't forget, the Bible lists many fasts. Even Jesus fasted.
I believe another reason the Master-Cleanse is well written is because it requires AT LEAST 10 DAYS.
I have broken many cravings (chocolate, sweets, etc.) being on it this long.
Mothers are very protective, no matter how old their 'babies' are.
I have not told my mother or my mother-in-law (and I am 36).
I know if I told them, that Mothering hormone would kick in and they would do anything they could to break my fast (tempting food, guilt, and oh...the audible worrying).
I believe the main reason they would is because they don't understand all this yet.
I hope once I'm off this and they see the results (weight loss, clear skin, energy, lower cholesterol) and explain exactly how I acomplished it, they might try it too and be healthier.
Some friends and relatives will throw up road blocks while you are a 'work in progress'.
Have your mom read through this website. There are so many success stories just using good food (not pills made in labs).