@TheGibson This might sound weird, but an older Thinkpad convertible tablet with stylus might work. You can install a minimal Linux and Krita, which is a wonderful open source tool used by many professional artists already. She can find answers to questions about it because it has such a wide user base

I use a Thinkpad x220 tablet to draw and write, but there are other convertibles on eBay that are cheaper than a lot of new tablets