Why go to the trouble of a flashlight/torch why not a chem light stick. I can't see a one year old breaking it open (concerns of chemical content spring to mind) and it will last longer than her attention span, waterproof, plus it's relatively cheap.
If you do want a light then try the glotoob or krill lights, these will keep your child amused for a while, until she's finished then you can stick it in you kit.
At the moment my 21mths plays with my watch with a blue-back lite, which she finds fascinating. It's waterproof to 200m, (personally taken it to 66m in the Med) and is all but indistructable not totally childproof but nearly.