Where is the Apple Watch face sleep preference?

My wife and I each have Apple Ultras. My sleep preferences are set for between 9 PM and 7 AM. During that time, my watch face (otherwise always on) is black. Time is accessible by tapping the face (I wear it at night). If I want to access other functions, I press and hold the crown. I like all those features.

My wife's watch, however, doesn't do any of this. She has a sleep setting, but her watch is always on, even at night, draining the battery.

I've tried looking for the differences between our preferences and can't find the one that turns the display black during sleep.

Can anyone help?

Thanks.