"Time spent thinking" is actually a great metric for getting smarter. However playing mental chess is probably way too difficult for her and the majority of the

"Time spent thinking" is actually a great metric for getting smarter. However playing mental chess is probably way too difficult for her and the majority of the population. A great way to understand how to get mentally fit is to look at physical fitness. For most unfit people, exercising muscles that they don't use is unpleasant. What they need is simple exercises that are short, easy to understand, repeatable, cover a range of muscles, and have variations that provide increasing difficulty for advancement. You don't want to start someone off doing power lifts. If you've been to any gym classes, you'll realize that there's no such thing as an objective scale for exercise difficulty. Squats may be trivial to someone but impossible for someone else. Finding a person's level of fitness and figuring out a good set of exercises that are appropriate for their progression is the key to a good long term fitness plan that actually works. How about starting her off with something simple like sudoku? I know some may balk at the idea of sudoku being a mental challenge, but it's the mental exercise equivalent of yoga. The reality is that some people who haven't used their brain in a long time may be at a very, very low level. Not a knock on them, just not everyone has the opportunity to use their mental faculties 8hrs a day at their day job.