Unless you are the parents of this girl, then it is not ridiculous...
If she is alive, it’s wrong to kill her. If she’s dead, it’s wrong to keep her rotting corpse partially functioning on machines. This is true, no matter who her parents are. The issue is whether she’s alive or dead.
It is beside the point, and ridiculous, to argue over who has the right to kill a living patient. Nobody does.
It is beside the point, and ridiculous, to argue over who has the right to abuse a corpse by keeping it hooked up to machines in an attempt to make it appear alive. Nobody does.