There is not one thing listed (because no requirements were given) in the OP that, say, a 2012 Macbook Air running Mojave in an HFS+ partition could not easily handle. She's a student. She's going to be typing and web-browsing. Instead of a $2000 laptop, buy a far cheaper used one from CL or FB, and pick up an Easystore external drive from BestBuy to daily clone the OS into (via an older copy of CCC). (Suffice to say that an older OS would permit her to run thousands of 32bit apps, not just AppStore payware.)