So sorry. Hope things go well from now on I have found with twins, its often the case the female is weaker, and smaller. Have lost a few myself over the years. Old sheep farmers taught me a few tricks, such as tickling up each nostril with a piece of straw, and swinging the kid by the back legs a few times. Believe me, I have tried all sorts with a lifeless kid, and sometimes you see a sign of life for your efforts. To be honest, anything is worth a go at a time like this. You obviously did all you could, but its still very sad to lose an animal.