Saying that though, bioshock is a good play, we managed so she might enjoy the chaos, never know.

I'm not 100 percent sure what's available on steam deck I've never really looked but if she's into fps then dead space, prey, or dishonoured.

Death stranding is a great play once you get past the start and that gets you used to the double sticks fast, as you have no choice.

Or if she wants a bit of an adventure I picked up ni no kuni wrath of the white witch remastered and that was brilliant, by studio ghibli too so the story is very well done and presented. I was surprised how much I enjoyed it and I'm old enough to remember studio ghibli old stuff being released. I even picked up ni no kuni 2 after it.

Or final fantasy series, they're all pretty forgiving.

Hard to decide lol, maybe give her some quick views on everything and let her see.

Zelda series on switch, both great. Or super Mario all stars, they were all decent, luigis mansion.

Idk if you have a 3ds handy but there's a game on there I started my partner on called fantasy life, it has a coop side to it so we did hunts and side quests together.

If not then you could try it takes two, or go old school and stick her on banjo kazooie, all the best players grew up with the good shit, so I'd start there.

Plus banjo kazooie is great.

Depends on what she's into too really, find something that suits her taste.

Humans fall flat is a good one too