Don't start with a framework. They should learn ES6 first - learn what has changed in the native language.
7 years is a long time. They also need to update what they know about HTML and CSS; they need to know what a modern browser's capabilities are; and learn a basic tooling setup like using npm+gulp.
A lot of fatigue about the current state of play is that you don't write the file that ships to the browser. You write abstracted code and use tools that do linting, transpilation, bundling and so on that ultimately spits out the file(s) you ship to the browser.
If you don't know how to use the tools, you are toast trying to get any modern framework running. You'll spend hours just trying to set up the environment and no time learning to make something.
So, they should learn ES6, in a single file adding interactivity to a page. Then they should use something like Gulp to run eslint on that file. Then add Babel to produce a backwards-compatible version of that file...
Build up from the basics. You don't learn to drive in a racecar.