Everyone else's suggestions are great.
Get them a copy of Factorio, it's a game, but it's all about computer science fundamentals, architecture, pipelining, busing, data integrity, etc. It's a visual game, but it'll scratch the itch of programming. It'll get them to think.
Buy the hardware projects, the little ones with either a pic, an Arduino, something that does something physical. A little bit of programming. To make a thing happen. So they can experiment.
Look at the software robot competitions, there's a couple on steam, there's couple elsewhere, you can do it as a family project, whiteboard out the logic of what your robot will do, and you can write it together. And see how it acts.
Just make sure anything you get, has a very small feedback loop, so they can iterate very quickly. That'll keep them engaged and exploring. You don't want to get a daunting project that's going to take weeks to see any output. You want things on the order of minutes, or even seconds to see what happens