I must confess I am at a disadvantage (or perhaps a bias) here. I have had tremendous opportunities in the workforce which I acknowledge are not average. I have also used my initial work opportunities to leverage my way to even better work opportunities and so therefore have managed to kinnear* those opportunities into further opportunities which have given me a foothold in Corporate America (TM) which a person of my age is not usually afforded. But, caveats aside:

At her level of experience, these are likely to be retail or volunteer.

I find people tend to forget the "back office" side of many jobs. For instance I work in the back office of a bank. The bigger a company, the bigger and more sprawling the "back office" is. If you aren't aware of these hidden back offices, you won't think to apply for them - and there the mystery is. These jobs are out of sight and out of mind but very real and occasionally very well-paying, certainly at least on par with the average retail role, but in general at minimum better for quality of life, and with better opportunities for advancement. You don't have to deal with customers or if you do, it's in a much more minimal role than a direct customer-facing role. You work 9 to 5 hours, which sure that might sound like 'slave labor' or 'buying out' but you know what? The hours are always stable and will never get in the way of your social life. You can get into these jobs with virtually any degree. I had a manager at a bank whose major was Etymology. My own major is (perhaps of course) in English. You all know what I do and how unrelated it is.

Banks have these jobs. Big box stores have these jobs; that's what "corporate" is - the back office. Hell I just linked an article not too long ago about Target and their analytics department. Would you have ever thought Target had an analytics department? But they do. The insurance industry is another big one for this, but most places have some sort of back office where you don't have to deal with customers. You deal with more etheral, less tangible things, like say compliance. Or analytics. Or whether or not an insurance claim or a bank claim is fraud. In these situations, I assure you, your liberal degree will not top you out at $40k a year. No graduate degree is necessary, though if you have a nice company, they'll help you pay for it.

I'm not saying there are jobs all over the places in these industries and again I stress that I was very lucky in getting my job - but these jobs exist. It's not all retail or specialty knowledge, especially if you can impress an interviewer with your personality, your knowledge, your ability to communicate - in other words if you can interview well. For a long time I felt I didn't deserve my job and that I brought nothing to it. You know what? They hired me anyway.

Long story short I don't think it's all retail vs. specialized knowledge. I think there are jobs people forget about and jobs people don't know about, jobs that don't have minimum requirements for majors, just jobs that seem boring and unappealing.

*This is a made-up word. In this context, I use it to mean something approximately like "finagle." There is a backstory here and here but I have further appropriated the word from "stealthily photographing someone" to mean "stealthily/trickily doing - anything."