I'm upset that my wife won't sleep
Why do you think that she won't sleep?
It's because she has slept more than 7 hours already today.
Different people need different amounts of sleep and it's wrong to get upset just because your wife doesn't need the same amount of sleep that you do since it is something that she cannot consciously control. Rather than getting upset, talk to your wife how you like to fall asleep next to her and try to work out a compromise. She can read while you fall asleep and then go to bed later when she is actually tired.
I don't want any disturbances while I'm asleep. It's not like I'm a machine. I need to rest too!
Maybe she is just not tired so she cannot go back to sleep. You should not get mad at her over something that she cannot control.