I would talk to your friend about it.
Not everyone process serious news in the same way.
I have a friend that I wonder about time. We are good friends and I often wondered if she would be there when I needed it.
One night while pregnant with my son, I had a bleed necessitating a run to the ER and my husband was out of town. I called her up--now she had been drinking....but her husband was home and I just needed help with the kids. So she decided to go with me to the hospital while her hubby watched the kids.
I did drive--and she was extremely funny and great to have around that night. Everything turned out fine.
But sometimes when I try to "plan" that I need her for something--she never seems available.
But when I need her at a moment's notice-she's there.
I'd chat with your friend.
*******
I've been dumped by a (different) friend. To this day I am confused as to why. She called me patronizing. Turns out she is one of those types who ALWAYS has people over and EXPECTS reciprocation. She was several years older than me and I was newly married and it wasn't something I was used to.
Getting dumped was completely unexpected and was done so quite harshly (she demanded maternity clothes she had loaned me back. So I promptly returned them and went shopping--only to be later told that she didn't mean immediately. However her very mean words indicated otherwise).
To this day I still mourn the loss of that friendship b/c she never bought ANY issue to my attention.
So now I tread carefully in ALL friendships.
I just wish she was enough of a friend to clue me in. What she did was callous, cold, and mean. I did learn some lessons and over 10 years later I haven't been dumped by anyone else.
Talk to your friend before your dump her. She may not have realized the impact of her words on you. Not everyone can drop everything in the name of friendship regardless of what the matter is.

for what you are going through. Give your friend another chance to help you through this difficult time.