Trying to use parts of Baptism dress for First Communion Dress …

My daughter's baptism dress had a long very full skirt made of a sweet cotton dot with lace at the bottom. I attached a photo. Because she was 3 when she was baptized, the skirt of the dress still fits at age 7. I really would like to use it for her First Communion dress this year, for sentimental sake, but am trying to figure out a new bodice - since the original bodice *is* too tight. I will probably use either the Fairy Tale dress bodice or the Library dress bodice pattern, both of which fit her well. And just attach to the original skirt. The problem is the fabric. It'll be impossible to match the skirt fabric and even a plain white will likely not be the same tone white. I'm having a hard time figuring out something suitable. I'd love any ideas. What about a plain white, with organza over the top? I also thought about maybe jersey, but that seems casual. Would love your ideas... thank you so much!