Pregnant women have died for as long as we have had pregnant women, this is the first time anyone has ever misguidedly, attempted to maintain a fetus in a dead woman.
If you go back to page 2 of this thread, there are some examples of other women who died during pregnancy and were kept on life support. Check Sammilee's post number 7663.
Researchers from Heidelberg University in Germany scoured the medical literature for cases of pregnant women who were kept on life support after being declared brain-dead. They were able to find details on 19 such cases that were reported from 1982 to 2010.
Of particular interest:
There were also two cases involving fetuses that were 15 weeks old when their mothers died. One of the fetuses died in utero 49 days after its mother suffered catastrophic bleeding in the brain in Italy in 1992. The other remained in utero for 107 days – more than 15 weeks – after its mother suffered a traumatic brain injury in the U.S. in 1989. That baby boy was delivered by C-section at 32 weeks; he weighed 3.4 pounds, had Apgar scores of 6 and 9 (scores lower than 7 indicate a newborn needs medical attention, according to the National Institutes of Health), and was developing normally 11 months after his birth.
I don't know how much hope there is for this particular baby. We will have to wait to see. But the above two examples show outcomes for babies in similar circumstances and gestational age, to the current baby, at the time of their mothers' deaths.