I'd move the buck out of the doe pen if you have a small herd of does. Kidding smells are attractive to bucks and when she can't run away, he will harass her/breed her while she is trying to have kids. This can obviously lead to problems. In a large herd, she is more likely to be able to wander away unnoticed, and he'll be more distracted by what the rest of the herd is doing. In a small herd, a buck is able to pay more attention to each doe individually, and is less likely to miss things. Good for breeding, but potentially bad for kidding events when she and her kids don't need to be harassed