If your mom have upset stomach, try to avoid any cold foods or drinks. Not necessary to eat or drink anything hot but at least in room temperature (even salad). When you cook vegetable soups for your mom, add some ginger. You may also try to make some ginger tea for her
here is the recipe
http://www.maangchi.com/recipe/saenggangchaRemember don't serve the cold version, try the hot ginger tea and make sure you get high quality RAW honey to use in this recipe.
If her stomach issues getting better, try to reintroduce fresh fruits and vegetables juice, you can also add ginger in the juice and before you make the juice, make sure all the fruits and vegetables are in room temperature, so you may have room temperature juice to serve your mom.
I know dandelion and milk thistle are good liver tonic but i don't know are they good for liver cancer.