First of all, I don’t know what your mother’s attending physician explained.
Radiotherapy and chemotherapy can have a huge impact on the body, especially the immune system. At this time, the patient's immunity is very low and comprehensive nutrition is needed to enhance the body's ability to withstand stress.
Each meal must have high-quality protein. It is recommended to choose fish, various beans, nuts, pumpkin seeds and other foods. Livestock meat is not easy to choose because the digestion capacity is not good at this time.
You should have a lot of fresh fruits and vegetables every day. You can mix and squeeze them into juices, which are easier to absorb. Use at least three kinds (including vegetables and fruits) every time, and of course eat some. If you choose, you can eat carrots, broccoli, purple cabbage, apples, pineapples, etc. You can also eat bananas, and you can also squeeze watermelon juice. In short, many choices.
Grains are also very important. Since your mother has just finished radiotherapy and chemotherapy, you can choose less coarse ones, such as brown rice. You can use millet, oats, buckwheat, etc., and mix them to cook porridge.
Nutritional supplements are equally important, such as deep-sea fish oil, wheat germ powder, flaxseed, vitamins B, C, E, etc. Try to choose trustworthy ones. Of course, it is just a supplement, and diet is the basis.
Finally, I have to say that since you have received treatment, please follow the doctor’s advice.