Oh! And if she’s into puzzles, look at Islands of Insight. First person with puzzle solving as the main mechanic, but also some exploration and a bit of mystery to it.

I’d consider what kind of game she finds fun and compelling–that’s more likely to engage her to become familiar with the mouse/keyboard combo.

That being said, Minecraft on peaceful mode would fit and is generally approachable. Stardew Valley is pretty relaxed as well, though I don’t remember whether it uses WASD specifically.