Feeling Stressed

I have my own issues but I'm very concerned for a work colleague and I was wondering how to express it/think of it/help  her, so I thought I'd just write.  I work in a big school and one of the ladies who works everyday and has been there for years, just turned 50 and went to go get checked through Breastscreen. It came back as STage 4 and metastatic ; hips, spine, lymph nodes.  Trouble is, this hardworking , dedicated mother of 2 adult girls, won't accept anything; saying doctors don't know anything/i'm fine/ i'll be ok just give me a bit of medicine etc.. She's started chemo but still seemingly unaffected. I don't work directly with her, but her closest people are worried about her. I guess she will do what she wants until she can';t. We want to help but can't. Any advice? Others