When we become old, we sometimes become children again. Find a flashlight designed for children for your mother; there are also well made, suitable for not strong hands. For autonomy, buy more than one, if you find 3 or 4 flashlights of different colors in your home, when one is unloaded, take the other; the ideal one is a torch in every room.
Or (always one in each room or however from 3 to 5) use those for diving use, have a lever switch, large and lightweight, only one mode, are robust, are found using AA or even 18650
