Beatrix

Beatrix was the second wife of Karlheinz and the mother of Shu and Reiji.
It is seen that she loved both of her sons but she is scared that Reiji is weak, and that's the only reason why she was strict with him.
Even though Cordelia despised Beatrix, Beatrix didn't feel the same for Cordelia which is why when she was assassinated, she died smiling, being freed from her guilt of neglecting Reiji and putting too much pressure on Shu as well as from Cordelia's torment.