This Boob Hat just had to be knit. I've seen it in several version, both knit and crocheted. Here's my own pattern for the Boob Hat / Breast Beanie
Finally I can breastfeed discreetly.
The Breast Beanie fits Thora at age 2 ½ months with a head circumference approx. 40 cm. It's knitted on a 4 mm needle with a knitting gauge of 20 stitches per 4 inches in stockinette stitch.