By the way, it's almost impossible to make a lightly sweetened carbonated cider using traditional ingredients and processes.
First, it's very difficult to stop a fermentation at a certain point and keep it there. It's like stopping a train. Secondly, if you do manage to stop it, the yeast will not then be able to work to carbonate the cider.
If you want a lightly sweetened, bottle carbed cider, you let the fermentation finish. It'll be a bit too dry, so you can then add some non-fermentable sweetener like lactose or splenda to sweeten to taste. Don't stir, or anything like that. You take samples of the cider, and mix up a simple syrup of water and sweetener, and then find the one you like. Then, take the SG of the sample, and sweeten it to just under that. (It seems to get sweeter in the bottle). So, if you like it at 1.010, you can sweeten the batch to 1.008, for example. You rack the cider gently into the sweetening solution. Then, you can prime it and bottle it, using a prescribed amount of fermentable sugar by racking it into that as well.