…I recommend the Professor Layton games on the DS.
I grew up with puzzles books and 3D puzzles, my mom loved them mainly and spread the love to the kids.
They are fun, little mysteries, incorporate over a hundred little brain benders of various classic types (match moving, logic, lateral thinking), and it’s digestible in little chunks. And, like ALL games should do, gives you a recap of where you were when you last stopped playing.
And guess what? My mom is playing it, too! Nothing like a senior citizen rockin’ on a DS! 🙂