I'm not sure what you mean by "represented"? Someone who doesn't have a job in order to be a caretaker or keep up a household would count as not employed, even though those people are still doing work. (The same would apply for people without jobs and spend their time in school or volunteering.)

They do ask why people aren't working in government surveys, so that information is available to analyze. I wasn't able to quickly find an overall recent figure, but there is a figure for people who are technically in the labor force but haven't looked for work in the last month: https://www.bls.gov/web/empsit/cpseea38.htm. And I also found an older figure: https://www.bls.gov/opub/btn/volume-4/people-who-are-not-in-....