A major hospital has other people that can work in a lab. People don't automatically die when she's not there and I assume that she can sometimes take vacation or a sick day.
Nope. There are no substitutes for graveyard 7 on 7 off for 10 hours a night.
If you ask her alternate week worker to take it while she's on jury duty for a week, that person would have to work 21 straight 10 hour nights with nothing off. They won't do it.
If the lab results aren't there when the Drs check in early in the morning, people will die.
Now, she could serve on her off weeks, but the court doesn't schedule trials based on the work schedule of jurors. That's why retired folks make perfect jurors. Every day is an day off.
Except for golf. I ain't giving up my Wed. golf date for a trial.