I had both the alpha herm and the beta pregnant, and the text for both birth events was the same, referring to "the female" giving birth. Could there be a bug reusing the beta text for the alpha herm?
They do share texts, but from what I can see, if both are indeed pregnant and giving birth, the Alpha should take precedence and the couple instance of "female" should be swapped out for "herm". If you have a save file that can reproduce this issue, that may be helpful.