I ended up with D for the half as did my sister. I'm guessing B for myself the 10k, but looking at some images via Google, my sister may be A for the 10k.
5k is a bit weird to me. I put my regular 5k running pace (~9:45/mile) as an estimate, just in case my DD7 weren't doing it, I'd rather start sooner than later. But I put hers as what it should be. I figured I'd drop back. But, our bibs are a pretty high number and only 10 digits apart, so I'm thinking we both got C or even D. It's fine, I would drop back anyway, just another oddity.