Witcher 3 is perhaps a good option. The combat style is relatively complex I’d say, and quite fun. The story is very engaging and super well written. And it’s available on both Steam and in fact on Switch too. I’ve played the whole game on Switch, and it runs well.
As a gaming mom myself, I’d second the Steamdeck recommendations. I love mine! Best thing I have bought in years honestly.
I can play in the living room, while hanging out with the rest of the family, and I take it with me on work trips as well. I don’t have Valheim on it, but I do have No Man’s Sky and it works well. I’m currently playing Baldur’s Gate 3 on the deck - there are so many great options.