College student here. There’s not a whole lot she can do now in high school. My advice is for her to get involved with any residence life stuff freshman year. For example, at my school, freshmen can be elected to hall government positions which is a good way to get your foot in the door. My RAs were very active in res life stuff last year. This is going to var per school so she really shouldn’t worry about it until she’s in college. Something she should definitely do is talk to her RAs and ask how she can get involved and become an RA. They would be able to provide the best, most relevant information.
At my school, RAs aren’t paid, they just receive free room and board. I think this is the standard for many schools. I definitely wouldn’t say it’s less stress. It can be a pretty stressful job. Definitely more stressful than my job (working in an advising office). My dorm had an issue at the beginning of the year that led to the firing/resignation of many RAs so the ones left had to work extra and cover the floors without RAs until new ones were hired. It was a very stressful few weeks for them. That’s definitely not the norm, but it does show how there are always different situations that can arise and you never know what will happen.
Really, it just depends on the school and it’s definitely way too early for her to think about this.