Prayer for my Mother

Please pray for my mother. She has 2 fatal illnesses. Stage 4 cancer and end stage congestive heart failure. She is currently in hospice. I don’t know which will end her life but the congestive heart failure makes her lung fill up with fluid and she feel like she is drowning. This causes her anxiety. It seems so cruel. Please pray that the God will be merciful and not let her suffer anymore.