Dark Brahma Sexing
Dark Brahmas are easier to sex than lights or buffs because the male and female feathering is so different. Brahmas can be slow to mature, but the feathering will be different early on for Darks. Females have lacing and penciling pattern all over. Males have solid or mostly black chests and white shoulders.
Too young yet. Once the chest start feathering, you should be able to see if the feathers are solid black (male) or penciled (female).