Your relationship to the person on whom you are spying matters. If that person is your child or your employee, you have a lot more leeway when it comes to monitoring their activities. If you think someone is spying on you illegally, file a report with local law enforcement so they can investigate your case.
Most cats snooze around 16 hours per day. The majority of their sleep time, however, is much shorter than the typical seven hours or so that humans average at. night. Cats tend to sleep lightly, without going into a deep sleep.
Cats sleep about 14 hours out of 24, but not all at one time. Many are fairly nocturnal and active at times during the night. There's a reason for the expression catnaps. Can't really MAKE a cat sleep. But cuddling and petting and grooming and making her comfortable calms her down and sleep often follows.