I finished a blue 'Millie pattern' dress using left over pieces of material I had from patchworking projects. The plain dark blue material was purchased from Ikea, but the spotty material is available in all good patchwork suppliers. Both materials are cotton.
You can purchase the pattern from Frocks and Frolics, see the button on the right hand side. That takes you direct to the website where you can download the pattern yourself. Also available are excellent video instructions, which you can follow from start to finish. Have fun!
This is the 1/2 size, but other sizes are available too.