Hi,
I am sorry to hear about the medical condition of your mother . Well, from what you describe - this is stage 4 cancer with widespread metastasis involving multiple organs. The prognosis in such cases is very bad , though nothing can be said about the time frame.
You should try and make her comfortable and spend time with her. You neeed to be strong so that you can support her at this time.
Do not panic and make these moments memorable for her.
Best regards.
I am in a similar situation with my dad. Unfortunately, there is not much you can do, but to take care of your mom and allow her the comfort of hospice and you to get through this. She will be well taken care of with Hospice and she deserves that. It is a horrible, dreadful thing, but we must let them go. God Bless.