Games that I played with my wife that wr thoroughly enjoyed
--------COOP--------
-Unravel two.
Great cute platformer where it doesn't matter if one player isn't that great at platformers. A mpving stoey with beautiful graphics and fun coop.
It Takes Two
A platforming game with a great story. Good feels all around
-Stardew Valley
Many people already suggested this. It's amazing. Super addictive, great coop, but can be played singleplayer as well if you're not around
- Trine series
Another great platformer series. Difficulty can easily be adjusted (by allowing lifting boxes with people on it with wizard). And can also be played solo.
Escape Simulator
Great escape room game with many small escaperooms that take about 10 to 15 minutes each to solve. Solo and coop.
-Overcooked
Great hectic coop game. I find this game quite hectic and exhausting to play for a long time, but my wife couldn't get enough of it. Even when she was tired. Best to play coop, can be played solo.
-------SINGLEPLAYER-------
My wife enjoyed management style games a lot, where you had no time pressure of any sorts.
- Strange Horticulture
Puzzle game where you try to find the right plants by deductions. No time pressure, very relaxing. Only single player, although you could play it together.
Planet Zoo
Probably the best zoo management game out there. Wife was addicted to it for months
Planet Coaster
Same as above, but with theme parks
Cities Skylines (first one)
Great city planner
Hope this helps!