There are several pencil kits that are top notch in my opinion. I keep 2 pencils on my office desk, a BHW El Grande which uses a Schmidt mechanism and a PSI Executive. The El Grande is a larger pencil, about 1/2" in diameter, and it is quite light, weighing no more than the Executive which is about 3/8" in diameter. You can also get 2 very classic pencil kits from BHW; one is styled after the 1940's Parker Twist pencil, called the All American Flat Top Double Twist and the other is styled after the German Mont Blanc Meisterstuck Classique twist pencil call the European Round Top Double Twist pencil. All 4 of these are lovely pencil kits and any of them would make a very nice birthday present for your mother-in-law. Just a note, the El Grande is convertible to a Parker-style ball point just by removing the pencil mechanism and inserting the ball point refill.