Doing really well but it's never far from the surface

Totally understand where you're coming from - I'm still in the chemo phase of treatment but often can't find the words now to offer comfort or advice.  And agree wholeheartedly with your comments on the PBS post - this is a support site not a battleground.
I hope your fears settle down again - I'm sure your friend didn't realise she was stirring things up - she probably thought she was being caring, or maybe she has something about her own health on her mind.  Take care - Egypt sounds so exciting!