Kristin,
I'm so sorry your friend is having to deal with this shocking diagnosis. And that's just what it is - shocking.
I agree with everything that has been said here by others, and would also add the following.
I think it is premature to be setting "timelines" before she has even begun treatment. Many women on this site are outliving their prognoses with great quality of life. Don't give up on that camping trip yet!
She needs to know that there are many good treatments out there that can work well and for a long time. In my opinion she should get the brain MRI. IF (and that is not a foregone conclusion) there is cancer there, most chemo drugs are not effective against brain mets because they do not cross the blood-brain barrier. However, there are other treatments for brain mets which can be very effective when found early.
The most important thing you can do for your friend is just what you are doing - love her and be there. As she gets more information and begins treatment, there will be more and more you can do in terms of "practical support" but just knowing you are there is HUGE. I came to learn that when people gave me rides or meals, what they were ACTUALLY giving me was love.
I highly recommend you check out the following website and the book "Fight Cancer" by Richard Bloch who was given the cancer death sentence and then died of something else many many years later at a ridiculous old age. You can actually download the book from the website. This book has excellent advice for how the patient, family, and other supporters can mobilize for the fight.
http://www.blochcancer.org/
Another good book is There's no place like Hope by Vickie Girard, a longterm survivor of Stage IV bc. This book really helped me.
This site is also a really wonderful, hopeful and intelligent place and I encourage you to visit again and bring your friend! There are lots of experienced and knowledgeable women and men here to make the journey easier.
Above all, do not lose hope, and do not let your friend lose hope.
Take care
Chris