My mom is a janitor.
That's cool. Where does she work? Janitors work in hospitals, schools and residential accomidations. 
She works at a high school.
Does she just clean? Sometimes janitors do maintenance and securitites too.
Yes she just cleans.
Apparently cleaning is one of the most commonly outsourced janitorial duities. 
Yes, she has done it for three years.
Does she work indoors? Most janitors do, but sometimes they work outdoors. 
Yes, only inside.
Does she think it is really dirty and unpleasant? There are a lot of people who think of that.