[deleted]

I think it would depend on the actress and the scene in question.

In some cases it wasn't real, and often they'd have the actress playing the mother facing away from the camera.

But there is one case where I think the actress really was genuinely lactating and had probably given birth some time before the show. It was in the first season of Outlander. There was a secondary character who had just given birth in the story and was helping the heroine out to find her husband, who had been taken by soldiers and they were attempting to track him down. In both the book and the tv show, the female character in question was forced to leave her newborn baby behind at home to help the heroine, and she couldn't afford to have her milk dry out while abroad, (which happens if you don't nurse for two days in real life), so she had to drain her milk into a cup every once in a while (I have no doubt she was saving it up to take back to her baby eventually). They only showed one scene where Jenny had to get off her horse and empty her girls out, because they hurt from being full of milk. The milk jetting out into the cup sure looked real to me.