As a non sewer you are really setting yourself up for some nail biting. I made the dresses for my three grand daughters to wear in my youngest daughter's wedding. I used the simplist pattern I could find. I then made an overshirt of white lacy fabric for the little girls to put over their cherry red dresses. It was basically a big apron that tied with a bow in the back. If you did something like that using the other dresses to make the overskirt or apron you could use a very basic plain dress underneath. You might even make a detachable collar or shawl like cape if you wanted more at the top.