Oh Susan, I'm so very sorry to read that they didn't make it. I am happy for your sake though that if they weren't going to make it they passed themselves so you didn't have to go through the further upset of having to put them down yourself. Sadly some of these little creatures just aren't meant to make it I think no matter how perfect we try to make the experience. Big hugs dear and like others have said, you are handling this with grace and professionalism in sharing it with us.
The remaining hatchlings are all that much more precious because of this experience.
It's a good question MeMe and one I'd be asking myself if I'd just gone through what Susan has with this pairing producing this clutch.
Personally I'd likely put them together again this coming season but also put Baba with a couple of other normal females and see how things go. If he sires normal offspring all around then maybe it was just a fluke thing. If he sires offspring again with this female that aren't healthy (but sires healthy offspring with all the other females) then I guess you'd have to assume that something genetic is triggered by their specific gene combination.