And disallow the possibility of a miracle?
It would be a miracle if a dead person NOT on a ventilator were to come back to life; would you say that such dead bodies shouldn’t be buried because burial would “disallow the possibility of a miracle”?
Well, by that logic, turn off the ventilator, because maybe a miracle will occur and she will keep breathing. There is no brain activity at all. Usually the reason they keep the body breathing even after the brain is dead is that if the family wants to donate the organs, if they are not oxygenated, they are not able to be donated.