I echo everything that ChristineB just posted, especially about the water.

A normal person needs 64 oz water daily. Healing/fighting makes severe demands on the system, and taking chemo exacerbates that significantly.

Have her get a 64 oz water bottle (I use old plastic V8 Juice containers, but any half-gallon container will do) and fill it first thing in the morning, and be sure that she drinks from it all day until it's gone.

It will also help her if she drinks an 8 oz glass of water when she uses the bathroom, first thing in the morning, even before brushing teeth or anything else other than answering the call of nature.

Water is required to keep the bowels moving (and unless you've had chemo, you can't imagine how important this can be. And if you have, you know what I'm talking about.)

It is also necessary to flush the byproducts of metabolism from your system and keep the blood from thickening as the healing/fighting process progresses.

In short, staying adequately hydrated is critical to survival. Just as the minimum caloric intake is.

Calories are needed for the extra fuel that powers the healing/fighting process; Water is needed to flush the byproducts.

Don't skimp on either! Doing so will make the process both more difficult, and more unpleasant at the same time.

Good luck, and my best wishes for a happy outcome!