Advice.. please..

How do you talk a person down from suicide when they have just witnessed their husband commit suicide and are about to pull the plug on their own flesh and soul 😞😞

A good old friend of mine is in a very dark place. Her two month old baby was hospitalized a month ago with shaken baby syndrome, is blind, now has cerebral palsy and will need feeding and breathing tubes his whole life and doctors are recommending she pull the plug on him. She tried six years for this baby. When he was diagnosed with SBS an investigation began of course and later revealed her husband was the one who caused it. He has problems and blacks out. That’s what happened. He didn’t remember causing the baby any harm and was wrought with guilt so he committed suicide in front of her. So she’s a mess. And keeps saying over and over that she won’t be able to go on if she has to pull the plug on her son. There are tons of people trying to help her but she’s just so far gone depressed. Idk what to do.