Canning No Cook Sweet Pickles?

My mother recently passed away and I'd like to duplicate her sweet pickles for the rest of the family. I know that she layered sliced sour pickles with white sugar, brown sugar and various spices--I have that part of the recipe. What I don't understand is this: These pickles ARE NOT cooked but she put them in canning jars and sealed them with a water bath. Did she do this to preserve them for a longer period of time? All the recipes I've found similar to this say to store the pickles in the refrigerator but I'd like to seal them like she did. Is this safe and why did she do it, I wonder? Any help would be greatly appreciated. Carla