She should probably buy a used office PC and used graphics card on eBay. Like a used Dell Optiplex SFF (Small Form Factor). The graphics card will need to be “Low Profile” in order to fit into a small case. You’ll also want the graphics card to run off 75 watts of power or less to run on the low-power power supplies of office computers, so an Nvidia card whose last two numbers end in “50” (and without any extra appelation like “Super” or “Overclock Edition”), for example. If you get a used graphics card on eBay, buy it from a domestic seller and at a not too-good-to-be-true price, to avoid “fake” graphics cards from China.
Here is a video which, while focused on regular-sized used PCs, outlines very clearly how to shop for the right speed of CPU in your used computer and what a reasonable amount of RAM is, etc: https://www.youtube.com/watch?v=v7oYLY8j03M
There’s also a website (just Google “CPU graphics card bottleneck”) where you can plug in your CPU and graphics card names and make sure they’re a good fit for each other.
I recently bought a used Optiplex with an i5 4590/500 GB HD/8 GB RAM, and a GTX 1050 Ti graphics card, for a total of about $260 shipped off eBay and I’m quite happy with the performance of the build. I think it’s about equivalent to a PS4 or so and it’s good for 1080p gaming. It could’ve been even cheaper if it weren’t for the pandemic.