No,wattles don’t determined gender,however length and color can detect male,escpecially in young chickens.Usually don’t see growth in combs and wattles till after eights weeks in pullets.By eight weeks cockerels usually are very red in that area and often wattles and combs are growing pretty big for the face.I don’t sex silkies but regular breeds usually are growing male fetahers by 11 weeks and that is the real answer,a wattles doesn’t determine,there are a lot of breeds with large combs and waddles at just four weeks and still turn out to be girls,very common for leghorn pullets to have big combs and wattles at a very young age.