She did give birth to the second one herself. What she didn't do was lick it and feed it.
You don't know that. Berkshire Boy only said that he came upon the calf dead.
It may be that the calf was born dead as the birth process took too long. I don't know if that is the case either.
But the
likelihood is that this cow will have trouble calving in future.
She'll be freeloading for another year now, probably 15 months, and there will always be the worry that tragedy may strike again.
Best all round to cull her