I agree Anke, last year we had a few problems, and at the time it seemed the easiest option to leave them running together, but come spring I seemed to spend hours working out when they may kid, ie what dates they were together (with breaks in the middle) and when he went, but they still caught me out, I did just happen to go in the barn as the smaller girl was kidding, and ended up just pulling a little to help her, leaving together is not something I'd do again.
Louis - are they seperated now or would it be possible to seperate them? at least that would narrow the kidding dates down, and then if they did come in season again they would shout for him?