The Marilyn dress is a size inclusive and made to measure pattern, this means you measure yourself and then follow the instructions.
The pattern is an intermediate level, however, may be suitable for advanced beginners as I have included pictures throughout each step.
You will need any type of 4ply (fingering) weight cotton yarn and a 3mm crochet hook. I used roughly 1200m of yarn for the sample size (XS -UK 6).
The pattern is in US terminology.