It might even be as simple as her not liking the taste or the temperature of the morphine.

and not recognizing the connection to that taste with regard to the pain going away.

My vote is for giving Nora as much agency as she wants, as long as what she wants is reasonable.

For example, when one of my grandmothers was in the hospital before her death, she wanted her catheter removed because she felt the need to urinate. I had to tell her over and over that, yes, it does feel that way, but it would allow her to pee. No amount of me explaining the process helped; she was mentally too far gone for that. I didn't want her to be uncomfortable, but I knew she'd wet the bed without it.

Then there was her roommate, who screamed every time someone tried to take her blood pressure, poor woman. :(