It can take 24h for the milk to drop, but usually earlier. Anyway, I just make sure the doe has peace and privacy and don't worry about that, or stress her with meddling or tire the kits by checking on them. Just one quick check of the nest, removing/replacing soiled or wet nesting material, and then I keep away. Some does will stay away from the nest as long as anyone is around. It is very rare that I see a doe nurse during the first weeks, usually only when I get there and she's already at it.