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.
It’s perhaps not a fully fledged fitness tracker, and it’s certainly not a smartwatch - but my favorite health tracking device has turned out to be my Oura ring.
I used it alongside my Apple Watch for quite a while, but I’ve found that the Oura ring gives me plenty of insight on my sleep, recovery and (more limited) activity. And the form factor is just awesome! I don’t even notice I’m wearing it, and I only charge it every 5 days or so.
I’ve stopped wearing the Apple Watch altogether now, and I find it freeing not to have all those notifications available on my wrist, while still having the health tracking I want from the Oura. Obviously it’s not a good fit for someone who does want the other features of a smartwatch, but solely as a health tracker I really like it.
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.