Circle skirt with tulle

I am making my girls flower girl/junior bridesmaid dresses for their uncles wedding. I am going to use the fairy tale pattern for the bodice. The bride has asked for the girls dresses to be long. I am planning on using a circle skirt. My younger daughter would really like to have a petticoat so it is "puffy". Would you recommend attaching the tulle to the dress lining like the directions in the pattern or should I make a separate petticoat? I am just wondering if the dress will be too heavy on a long dress. Thank for any advice! Sasha