Thare is a few ways to tell. Hackle feathers, comb and saddle feathers. I mainly use the saddle feathers. In most breeds males have pointy saddle feathers and females are round. I have some pictures for future references. They're not the best pictures but I'll redo it with better pictures tomorrow.
My porcelain d'uccles hen
Silver duckwing OEGB rooster
My vote is for pullet.
My porcelain d'uccles hen
Silver duckwing OEGB rooster
My vote is for pullet.