Sis, I too am praying. I have to admit, when I read what you mom is going through right now, it brought back bitter sweet memories for me. My mom was diagnosed with stage 4 colon cancer too, back in May of 2002.
And they gave her 6 months too. And don't you know she stayed here for 4 and a half more years!
It was not an easy journey. My dad was the ULTIMATE caretaker, and lived his wedding vows and showed absolute integrity and devotion during this time. I keep saying that I will write their story one day, it was so beautiful.
I come in agreement and pray that our precious Holy Spirit would come and minister to each one of you, you and your siblings and your dear mom. He will show Himself truly as Comforter during this time.