You can stack as many circles as you want as it will make the flower look prettier and fluffier.
Note : Make sure when you melt the edges of your fabric circles, your circles do not get intact with the flame as it will burn your fabric circles and you will end up with a black stained circles. Make it as close to the flame and turn it around till every edges is melted. Below is the video tutorial in How to make Lollipop Fabric flower. So enjoy and give it a try.