Would it be alright for me to ask my mum about what her life expectancy has been assumed to be?

Finn

Firstly, I'm aware that this is something that only I can truly know, but I wanted to get some advice anyway because I'm aware it's going to be a very sensitive topic for her to talk about.

For some background, my mum has stage 4 breast cancer, which has metastasised to her lung and bone. She was diagnosed almost two years ago. Treatment wise, she started with Chemo and Herceptin, but stopped the chemo after 6 or so months. She hasn't had any surgery, and currently the treatment plan is mostly about her retaining her quality of life, while still having minimal treatment to hopefully keep the cancer at bay. I'm aware that stage 4 is incurable, and that that is definitely the case for my mum.

I know what the general life expectancy is for stage 4, but of course it'll vary from person to person. I'm not sure if this is typical, but I would like to have a general idea of what my mum has been told in this regard for her specific situation so that I'm not blindsided by it possibly getting worse when it's expected to. I'm sure some of you have had similar conversations with family members, or maybe they've had the conversation with you, and I'm curious how you went about it. Any help is appreciated, cheers.