You can write, in the free-text box that every one of those forms has and that almost nobody uses, a sentence like: If I am unable to participate in a decision about my child, my sister is to be notified and present.

That is not legally binding on a hospital in most states.

It does not have to be.

What it does is put a piece of paper in a chart that a clinician will read, and once it is in the chart, somebody in that conference room says hang on, there’s a directive, and the whole thing changes.

I say that sentence in every class and I say it slowly and I watch about a third of the room write it down.

Two. Your medical record belongs to you.