@neeny Congrats on your results & rad treatment aint so bad so i reckon you are doing really well.
My mum has passed away but we chose not to tell my mother-in-law about my cancer, treatment or surgery as she has dementia & has also had breast cancer herself. She is mid 70's. My hubby didnt want her to worry, which she would have & as we live a couple of hours away, it was easy to keep it a secret. As it turned out, i am doing really well with no further treatment on the horizon so it was easy to keep it from my in-laws. I had 2 operations & 3 weeks of rad & they knew nothing about it. I really think the extra worry would have made her condition worse so very happy with the decision. I know it is a bit closer to home being your mum & i think the advice you have already received above, is excellent. At the end of the day, you have to be happy with your decision. You dont want her to worry excessively & make her condition worse but she is your mum & it would be hard to keep it from her. If you were requiring chemo, more treatment or extra surgery, then it may be tricky to hide the hair loss, hospitals stays but if you are only having rad, then half hr a day with very minimal side effects, can easily be kept a secret if you think that is best. Good luck with your decision & with your rad treatment. xx