even when my heart is breaking

My little friend's cancer has come back, and death is staring them in the face, only miracles and one slim clinical trial left for hope of life. Her mother wrote this last night:

I hold to the comfort that God will redeem this, and the beauty will one day outweigh the dark agony. I hold to the comfort that though I cannot see how, God will carry me, day by day by day. I hold to the comfort that He stands with me now. He stands in the circle of doctors doing rounds. He has not forsaken me. I pray that this ragged, gaping hole in my heart and gut will be filled with His grace and that somehow, in the very midst of what feels like my own death, God would overflow and streams of living water would meet the mouths of the parched. That out of this death, in its myriad of forms, life, life abundant would take root. Lord, hear my prayer.

And all I can do is pray, and hold my own children close, and cry for and with my friends, facing the impossible. I don't know what to pray for them, and my soul keeps going back to the Psalms, crying out to God:

Yea, though I walk through the valley of the shadow death, I will fear no evil,
for you are with me; your rod and your staff, they comfort me...
... Surely your goodness and mercy will follow me all the days of my life,
and I will dwell in the house of the Lord forever.