What's a good game for a 65-year old first time gamer?

My mum's only gaming experience has been Candy Crush Saga and Farmville.

To my great surprise she's just downloaded Steam and wants to play. I have no idea where to begin so all recommendations are very welcome but not FPS as I know she'll hate that.

Total blank canvas. Please help me start her off on the path to gaming brilliance. Thanks.