I think there’s a degree of cognitive dissonance at play.
She thinks she wants to “win” and have Archie’s heart stop whilst still being ventilated because the hospital wants a controlled withdrawal.
However, she doesn’t want his heart to stop, has been delusional for 4 months about his true status and if he is deteriorating she will be alarmed and desperate, not relieved that she will get what she said she wanted.
There has been 4/12 of deliberately NOT coming to terms with how she found him, how he is not going to recover. There’s been a lot projection of life onto a lifeless body - “breathing”, “looking”, squeezing hands, responding to her etc.
The moment of reckoning is going to be awful, and I agree with a pp that crying, raging, screaming and wailing would be an expected response from her.
Let’s hope that she doesn’t externalise her rage to extend to the staff though.