How big should a kidding pen be?

[HazyDay]

I, well dad and I plan to build another pen, as I had a very hard time keeping kids in pens where no one would get bred. Plus I need a kidding pen, as I hated trying to pull a kid in the doe barn with other does licking me and wanting so love

So anyways we are making another copy of the pen I already have. Is this a good size? I wanted it big so I would have room to help out and so the doe won't sit on her kids. I was worrying about having 2 does due on the same day, but well I tought she was bred and last night she was rebred

The size of the pen is this. (I do plan to make it able to be cut in half so I can keep newborns from being killed! )

4 1/2 feet W (<--->)
~~and~~
8 feet Long.

Thanks!