It is size S, 60-66 cm waist line. The belt is stretchy, so it is easy to add or decrease a size.
Worked in round. First the belt then top then skirt. Don’t forget to add ease.

The top chart is approximative, please allow yourself make a paper pattern (same for back and front) for it and follow it with your crocheting.
Straps are made from a fabric, but you can crochet them too.

You will need about 16 skeins of 50 gr or 2000-2300 meters and hook size 3-3.5 or whatever fit your yarn.