Hello there and thanks for posting

Whilst people who are unwell or have chicken pox should avoid contact with patients undergoing chemotherapy with a lowered immune system, if you say your son has already had chicken pox it is unlikely for him to get it again so hopefully he should be fine.

To be on the safe side your son may prefer to stay away from his Nan this week but I don't think you should be worried about seeing your mum unless you are unwell yourself.

Best wishes

Naomi