Wow what a selfless lady
I have read stories of children who have been diagnosed with this condition in utero and on birth it turned out that the diagnosis was wrong.
There is way too much diagnosis based on ultrasounds.
That is just not a reliable enough indicator to determine life or death of a child and the long term prognosis.
If the baby dies without any “help” from the medical staff, this is morally OK.
May God bless this family and welcome this baby into His loving arms.