Susurrus requirements:

Sizes: 1 (2, 3, 4, 5, 6, 7, 8, 9)
Finished chest (fullest point) circumference:
85 (95.5, 105.5, 116, 126,136,146.5, 153, 163.S)cm / 33½ (37½, 41½, 45¾, 49½, 53½, 57¾, 60¼, 64¼)“ - to be worn with 10-15cm / 4-6” positive ease.
(Check https://www.ravelry.com/patterns/library/susurrus-3 for measurements)
Note the mohair used in the original patterns comes in 25g balls.